Alphabetic List of Keywords

Note 1: Additional components of CPMD input files that do not fit into the following list are explained in the succeeding section 7.5.

Note 2: Keywords for the &QMMM section of the CPMD/Gromos QM/MM-Interface code are not listed here but in section 9.14.2.

ACM0

Section: &DFT

Add exact exchange to the specified FUNCTIONAL according to the adiabatic connection method 0. [78,81] This only works for isolated systems and should only be used if an excessive amount of CPU time is available.

ACM1

Section: &DFT

Add exact exchange to the specified FUNCTIONAL according to the adiabatic connection method 1. [79,81] The parameter is read from the next line. This only works for isolated systems and should only be used if an excessive amount of CPU time is available.

ACM3

Section: &DFT

Add exact exchange to the specified FUNCTIONAL according to the adiabatic connection method 3. [79,81] The three needed parameters are read from the next line. This only works for isolated systems and should only be used if an excessive amount of CPU time is available.

ALEXANDER MIXING

Section: &CPMD

Mixing used during optimization of geometry or molecular dynamics. Parameter read in the next line.
Default value is 0.9

ALLTOALL {SINGLE,DOUBLE}

Section: &CPMD

Perform the matrix transpose (AllToAll communication) in the 3D FFT using single/double precision numbers. Default is to use double precision numbers.

ANDERSON MIXING $N=n$

Section: &CPMD

Anderson mixing for the electronic density during self-consistent iterations. In the next line the parameter (between 0 and 1) for the Anderson mixing is read.
Default is 0.2 .
With the additional option $N=n$ a mixing parameter can be specified for different threshold densities. $n$ different thresholds can be set. The program reads $n$ lines, each with a threshold density and an Anderson mixing parameter.

ANGSTROM

Section: &SYSTEM

The atomic coordinates and the supercell parameters and several other parameters are read in Ångstroms.
Default is atomic units which are always used internally. Not supported for QMMM calculations.

ANNEALING {IONS,ELECTRONS,CELL}

Section: &CPMD

Scale the ionic, electronic, or cell velocities every time step. The scaling factor is read from the next line.

ATOMIC CHARGES

Section: &ATOMS

Changes the default charge (0) of the atoms for the initial guess to the values read from the next line. One value per atomic species has to be given.

AVERAGED POTENTIAL

Section: &PROP

Calculate averaged electrostatic potential in spheres of radius Rcut around the atomic positions.
Parameter Rcut is read in from next line.

BECKE BETA

Section: &DFT

Change the $\beta$ parameter in Becke's exchange functional [31] to the value given on the next line.

BENCHMARK

Section: &CPMD

This keyword is used to control some special features related to benchmarks. If you want to know more, have a look in the source code.

BFGS

Section: &CPMD

Use a quasi-Newton method for optimization of the ionic positions. The approximated Hessian is updated using the Broyden-Fletcher-Goldfarb-Shano procedure [26].

BLOCKSIZE STATES

Section: &CPMD

Parameter read in from next line.
NSTBLK
Defines the minimal number of states used per processor in the distributed linear algebra calculations.
Default is to equally distribute states over all processors.

BOGOLIUBOV CORRECTION [OFF]

Section: &CPMD

Computes the Bogoliubov correction for the energy of the Trotter approximation or not.
Default is no Bogoliubov correction.
The keyword has to appear after FREE ENERGY FUNCTIONAL.

BROYDEN MIXING

Section: &CPMD

Parameters read in from next line.
BROYMIX, ECUTBROY, W02BROY, NFRBROY, IBRESET
These mean:

BROYMIX:

Initial mixing, e.g. $0.1$; default value is 0.5

ECUTBROY:

Cutoff for Broyden mixing. DUAL*ECUT is the best choice and the default

W02BROY:

$w_0^2$ parameter of Johnson [69]. Default 0.01

NFRBROY:

Number of Anderson mixing steps done before Broyden mixing. Default is 0

IBRESET:

Number of Broyden vectors. $5$ is usually a good value and the default.

You can also specify some parameters with the following syntax:
[BROYMIX=BROYMIX] [ECUTBROY=ECUTBROY]
[W02BROY=W02BROY] [NFRBROY=NFRBROY]
[IBRESET=IBRESET]
Finally, you can use the keyword DEFAULT to use the default values.

CELL {ABSOLUTE, DEGREE, VECTORS}

Section: &SYSTEM

The parameters specifying the super cell are read from the next line. Six numbers in the following order have to be provided: $a$, $b/a$, $c/a$, $\cos \alpha$, $\cos \beta$, $\cos \gamma$. For cubic phases, $a$ is the lattice parameter. CPMD will check those values, unless you turn off the test via CHECK SYMMETRY. With the keyword ABSOLUTE, you give $a$, $b$ and $c$. With the keyword DEGREE, you provide $\alpha$, $\beta$ and $\gamma$ in degrees instead of their cosine. With the keyword VECTORS, the lattice vectors $a1$, $a2$, $a3$ are read from the next line instead of the 6 numbers. In this case the SYMMETRY keyword is not used.

CENTER MOLECULE [OFF]

Section: &CPMD

The center of mass is moved/not moved to the center of the computational box in a calculation with the cluster option. This is only done when the coordinates are read from the input file.

CENTROID DYNAMICS

Section: &PIMD

Adiabatic centroid molecular dynamics, see Ref. [62,63,74] for theory and details of our implementation, which yields quasiclassical dynamics of the nuclear centroids at a specified temperature of the non-centroid modes. This keyword makes only sense if used in conjunction with the normal mode propagator via the keyword NORMAL MODES and FACSTAGE $>1.0$ and WMASS $=1.0$. The centroid adiabaticity control parameter FACSTAGE, which makes the non-centroid modes artificially fast in order to sample adiabatically the quantum fluctuations, has to be chosen carefully; note that FACSTAGE  $= 1/\gamma$ as introduced in Ref. [74] in eq. (2.51).

CG-ANALYTIC

Section: &RESP

The number of steps for which the step length in the conjugate gradient optimization is calculated assuming a quadratic functional E(2) (quadratic in the linear response vectors). No accuracy impact, pure convergence speed tuning.
Default value is 3 for NMR and 99 otherwise.

CG-FACTOR

Section: &RESP

The analytic length calculation of the conjugate-gradient step lengthes yields in general a result that is slightly too large. This factor is used to correct for that deficiency. No accuracy impact, pure convergence speed tuning.
Default is 0.8 .

CHANGE BONDS

Section: &ATOMS

The buildup of the empirical Hessian can be affected.
You can either add or delete bonds. The number of changed bonds is read from the next line. This line is followed by the description of the bonds. The format is
{ ATOM1 ATOM2 FLAG} .
ATOM1 and ATOM2 are the numbers of the atoms involved in the bond. A FLAG of $-1$ causes a bond to be deleted and a FLAG of $1$ a bond to be added.
Example:

CHANGE BONDS
2
1	2	+1
6	8	-1

CHARGES

Section: &PROP

Calculate atomic charges. Charges are calculated according to the method of Hirshfeld [50] and charges derived from the electrostatic potential [51].

CHARGE

Section: &SYSTEM

The total charge of the system is read from the next line.
Default is 0 .

CHECK MEMORY

Section: &CPMD

Check sanity of all dynamically allocated arrays whenever a change in the allocation is done. By default memory is checked only at break points.

CHECK SYMMETRY [OFF]

Section: &SYSTEM

The precision with which the conformance of the CELL parameters are checked against the (supercell) SYMMETRY is read from the next line. With older versions of CPMD, redundant variables could be set to arbitrary values; now all values have to conform. If you want the old behavior back, you can turn the check off by adding the keyword OFF or by providing a negative precision. Default value is: 1.0e-4

CLASSICAL CELL [ABSOLUTE, DEGREE]

Section: &SYSTEM

Not documented.

CLASSICAL TEST

Section: &PIMD

Test option to reduce the path integral branch to the classical code for the special case $P=1$ in order to allow for a one-to-one comparison to a run using the standard branch of CPMD. It works only with primitive propagator, i.e. not together with NORMAL MODES, STAGING and/or DEBROGLIE CENTROID.

CLASSTRESS

Section: &CPMD

Not documented.

CMASS

Section: &CPMD

The fictitious mass of the cell in atomic units is read from the next line.
Default value is 200

COMPRESS [WRITEnn]

Section: &CPMD

Write the wavefunctions with nn bytes precision to the restart file.
Possible choices are WRITE32, WRITE16, WRITE8 and WRITEAO.
WRITE32 corresponds to the compress option in older versions. WRITEAO stores the wavefunction as a projection on atomic basis sets. The atomic basis set can be specified in the section &BASIS ... &END. If this input section is missing a default basis from Slater type orbitals is constructed. See section 7.5.3 for more details.

CONDUCTIVITY

Section: &PROP

Computes the optical conductivity according to the Kubo-Greenwod formula

$$\sigma(\omega) = \frac{2 \pi e^2}{3m^2 V_{\rm cell}} \frac{1}{\om... ... p} \vert\psi _j \rangle \vert^2 \delta(\epsilon _i -\epsilon_j - \hbar \omega)$$

where $\psi _i$ are the Kohn-Sham eigenstates, $\epsilon _i$ their corresponding eigenvalues, $f_i$ the occupation number and the difference $f_i-f_j$ takes care of the fermionic occupancy. This calculation is executed when the keyword PROPERTIES is used in the section &CPMD ... &END. In the section &PROP ... &END the keyword CONDUCTIVITY must be present and the interval interval $\Delta \omega$ for the calculation of the spectrum is read from the next line. Note that, since this is a "PROPERTIES" calculation, you must have previously computed the electronic structure of your system and have a consistent RESTART file ready to use. Further keyword: STEP=0.14, where (e.g.) 0.14 is the bin width in eV of the $\sigma(\omega)$ histogram if you want it to be different from $\Delta \omega$. A file MATRIX.DAT is written in your working directory, where all the non-zero transition amplitudes and related informations are reported (see the header of MATRIX.DAT). An example of application is given in Ref. [113].

CONFINEMENT POTENTIAL

Section: &ATOMS

Not documented.

CONJUGATE GRADIENTS [ELECTRONS, IONS, NOPRECONDITIONING]

Section: &CPMD

For the electrons, the keyword is equivalent to PCG. The NOPRECONDITIONING parameter only applies for electrons. For the ions the conjugate gradients scheme is used to relax the atomic positions.

CONSTANT CUTOFF

Section: &SYSTEM

Apply a cutoff function to the kinetic energy term [82] in order to simulate constant cutoff dynamics. The parameters $A$, $\sigma$ and $E_o$ are read from the next line (all quantities have to be given in Rydbergs).

$$G^2 \rightarrow G^2 + A \left[ 1 + \mbox{erf} \left( {\frac{1}{2} G^2 - \frac{E_o}{\sigma}} \right) \right]$$

CONSTRAINTS ... END CONSTRAINTS

Section: &ATOMS

With this option you can specify several constraints and restraints on the atoms. (see section 7.5.2 for more information on the available options and the input format).

CONVERGENCE [ADAPT, ENERGY, CALFOR, RELAX, INITIAL]

Section: &CPMD

The adaptive convergence criteria for the wavefunction during a geometry optimization are specified. For more informations, see [10]. The ratio TOLAD between the smallest maximum component of the nuclear gradient reached so far and the maximum allowed component of the electronic gradient is specified with CONVERGENCE ADAPT. This criterion is switched off once the value TOLOG given with CONVERGENCE ORBITALS is reached. By default, the adaptive gradient criterion is not active. A reasonable value for the parameter TOLAD is 0.02.
If the parameter TOLENE is given with CONVERGENCE ENERGY, in addition to the gradient criterion for the wavefunction, the energy change between two wavefunction optimization cycles must be smaller than the energy change of the last accepted geometry change multiplied by TOLENE for the wavefunction to be considered converged. By default, the adaptive energy criterion is not active. It is particularly useful for transition state search with P-RFO, where the trust radius is based on the quality of energy prediction. A reasonable value for TOLENE is 0.05.
To save CPU time, the gradient on the ions is only calculated if the wavefunction is almost converged. The parameter TOLFOR given with CONVERGENCE CALFOR is the ratio between the convergence criteria for the wavefunction and the criteria whether the gradient on the ions is to be calculated. Default value for TOLFOR is 3.0 .
If the wavefunction is very slowly converging during a geometry optimization, a small nuclear displacement can help. The parameter NSTCNV is given with CONVERGENCE RELAX. Every NSTCNV wavefunction optimization cycles, the convergence criteria for the wavefunction are relaxed by a factor of two. A geometry optimization step resets the criteria to the unrelaxed values. By default, the criteria for wavefunction convergence are never relaxed.
When starting a geometry optimization from an unconverged wavefunction, the nuclear gradient and therefore the adaptive tolerance of the electronic gradient is not known. To avoid the full convergence criterion to be applied at the beginning, a convergence criterion for the wavefunction of the initial geometry can be supplied with CONVERGENCE INITIAL. By default, the initial convergence criterion is equal to the full convergence criterion.

CONVERGENCE [ORBITALS, GEOMETRY, CELL]

Section: &CPMD

The convergence criteria for optimization runs is specified.
The maximum value for the biggest element of the gradient of the wavefunction (ORBITALS), of the ions (GEOMETRY), or the cell (CELL) is read from the next line.
Default values are 10$^{-5}$ for the wavefunction, 5$\times$10$^{-4}$ for the ions and 1.0 for the cell. For diagonalisation schemes the first value is the biggest variation of a density component. Defaults are 10$^{-3}$ and 10$^{-3}$ .

CONVERGENCE

Section: &LINRES

Convergence criterion for linear response calculations.
Default value is 10$^{-5}$ .

CONVERGENCE

Section: &RESP

Convergence criterion on the gradient $\delta E/\delta \psi^*$ Default value is 10$^{-5}$ .

CORE SPECTRA

Section: &PROP

Computes the X-ray adsorption spectrum and related transition matrix elements according to Ref. [114]. This calculation is executed when the keyword PROPERTIES is used in the section &CPMD ... &END. In the section &PROP ... &END the keyword CORE SPECTRA must be present and the core atom number (e.g. 10 if it is the 10$th$ atom in your list) and core level energy (in au) are read from the next line, while in the following line the $n$ and $l$ quantum numbers of the selected core level, along with the exponential factor $a$ of the STO orbital for the core level must be provided. In the case of $1s$ states, the core orbital is reconstructed as

$$\psi _{1s}(r) = 2 a^{\frac{3}{2}} r \cdot \exp (-a\cdot r)$$

and it is this $a$ value in au that must be supplied in input. As a general rule, first-row elements in the neutral case have the following $a$ values: B (4.64), C (5.63), N (6.62), O (7.62). For an excited atom these values would be of course a bit larger; e.g. for O it is 7.74453, i.e. 1.6 % larger. Since this is a "PROPERTIES" calculation, you must have previously computed the electronic structure of your system and have a consistent RESTART file ready to use. A file XRAYSPEC.DAT is written in your working directory, containing all the square transition amplitudes and related informations, part of which are also written in the standard output. Waring: in order to use this keyword you need special pseudopotentials. These are provided, at least for some elements, in the PP library of CPMD and are named as *_HOLE.psp

CUBECENTER

Section: &PROP

Sets the center of the cubefiles produced by the CUBEFILE flag. The next line has to contain the coordinates of the center in Bohr or Angstrom, depending on whether the ANGSTROM keyword was given. Default is the geometric center of the system.

CUBEFILE ORBITALS,DENSITY HALFMESH

Section: &PROP

Plots the requested objects in .CUBE file format. If ORBITALS are demanded, the total number as well as the indices have to be given on the next and second next line. HALFMESH reduces the number of grid points per direction by 2, thus reducing the file size by a factor of 8.

CUTOFF [SPHERICAL,NOSPHERICAL]

Section: &SYSTEM

The cutoff for the plane wave basis in Rydberg is read from the next line. The keyword SPHERICAL is used with k points in order to have $\vert g + k\vert^2 < E_{cut}$ instead of $\vert g\vert^2 < E_{cut}$. This is the default.

DAVIDSON DIAGONALISATION

Section: &CPMD

Use Davidson diagonalisation scheme.[83]

DAVIDSON PARAMETER

Section: &CPMD

This keyword controls the Davidson diagonalisation routine used to determine the Kohn-Sham energies.
The maximum number of additional vectors to construct the Davidson matrix, the convergence criterion and the maximum number of steps are read from the next line.
Defaults are 10$^{-5}$ and the same number as states to be optimized. If the system has 20 occupied states and you ask for 5 unoccupied states, the default number of additional vectors is 25. By using less than 25 some memory can be saved but convergence might be somewhat slower.

DAVIDSON PARAMETER

Section: &TDDFT

The maximum number of Davidson iterations, the convergence criteria for the eigenvectors and the maximal size of the Davidson subspace are set. The three parameters ndavmax, epstdav, ndavspace are read from the next line.
Default values are 100 , 10$^{-10}$ and 10 .

DAVIDSON RDIIS

Section: &TDDFT

This keyword controls the residual DIIS method for TDDFT diagonalization. This method is used at the end of a DAVIDSON diagonalization for roots that are not yet converged. The first number gives the maxium iterations, the second the maximum allowed restarts, and the third the maximum residual allowed when the method is invoked.
Default values are 20 , 3 and $10^{-3}$ .

DEBROGLIE [CENTROID]

Section: &PIMD

An initial configuration assuming quantum free particle behavior is generated for each individual atom according to its physical mass at the temperature given in Kelvin on the following input line. Using DEBROGLIE each nuclear position obtained from the &ATOMS ... &END section serves as the starting point for a Gaussian Lévy walk of length $P$ in three dimensions, see e.g. Ref. [60]. Using DEBROGLIE CENTROID each nuclear position obtained from the &ATOMS ... &END section serves as the centroid (center of geometry) for obtaining the centroid (center of geometry) for obtaining the $P$ normal modes in three dimensions, see e.g. Ref. [61]. This option does only specify the generation of the initial configuration if INITIALIZATION and GENERATE REPLICAS are active. Default is DEBROGLIE CENTROID and 500 Kelvin.

DEBUG CODE

Section: &CPMD

Very verbose output concerning subroutine calls for debugging purpose.

DEBUG FILEOPEN

Section: &CPMD

Very verbose output concerning opening files for debugging purpose.

DEBUG FORCES

Section: &CPMD

Very verbose output concerning the calculation of each contribution to the forces for debugging purpose.

DEBUG MEMORY

Section: &CPMD

Very verbose output concerning memory for debugging purpose.

DENSITY CUTOFF NUMBER

Section: &SYSTEM

Read the number of plane waves for density.
Useful to calculate bulk modulus or properties depending on the volume. The given energy cutoff has to be bigger than the one to have the required plane wave density number.

DIAGONALIZER {DAVIDSON,NONHERMIT,PCG} [MINIMIZE]

Section: &TDDFT

Specify the iterative diagonalizer to be used.
Defaults are DAVIDSON for the Tamm-Dancoff method, NONHERMIT (a non-hermitian Davidson method) for TDDFT LR and PCG (Conjugate gradients) for the optimized subspace method. The additional keyword MINIMIZE applies to the PCG method only. It forces a line minimization with quadratic search.
Default is not to use line minimization .

DIAGONAL [OFF]

Section: &HARDNESS

Not documented

DIFF FORMULA

Section: &LINRES

Number of points used in finite difference formula for second derivatives of exchange-correlation functionals. Default is two point central differences.

DIIS MIXING

Section: &CPMD

Use the direct inversion iterative scheme to mix density.
Read in the next line the number of previous densities (NRDIIS) for the mixing (however not useful).

DIIS MIXING [$N=n$]

Section: &CPMD

Like DIIS MIXING, but number of previous densities for the mixing can be specified as a function of the density.
$n$ different thresholds for the density can be set. The program reads $n$ lines with a threshold density and a NRDIIS number (number of previous densities for the mixing). Numbers NRDIIS have to increase. If the NRDIIS is equal to 0, Anderson mixing is used. Very efficient is to use Anderson mixing and afterwards DIIS mixing.

DIPOLE DYNAMICS {SAMPLE,WANNIER}

Section: &CPMD

Calculate the dipole moment [84,85] every NSTEP iteration in MD.
NSTEP is read from the next line if the keyword SAMPLE is present.
Default is every time step.
The keyword Wannier allows the calculation of optimally localized Wannier functions[22,23,110]. The procedure used is equivalent (for single k-point) to Boys localization.

The produced output is IONS+CENTERS.xyz, IONS+CENTERS, DIPOLE, WANNIER_CENTER and WANNIER_DOS. The localization procedure is controlled by the following keywords.

DIPOLE MOMENT [BERRY,RS]

Section: &PROP

Calculate the dipole moment.
Without the additional keywords BERRY or RS this is only implemented for simple cubic and fcc supercells. The keyword RS requests the use of the real-space algorithm. The keyword BERRY requests the use of the Berry phase algorithm.

DISTRIBUTED LINALG {ON,OFF}

Section: &CPMD

Perform linear algebra calculations using distributed memory algorithms. This is not available for most property calculations and non-random initial guess for the wavefunction. Default is to use replicated data algorithms.

DISTRIBUTE FNL

Section: &CPMD

The array FNL is distributed in parallel runs.

DUAL

Section: &SYSTEM

The ratio between the plane wave cutoff for the density and the wavefunction is read from the next line.
Default is 4.
Warning: You can have some trouble if you use the DUAL option with the symmetrization of the electronic density.

DUMMY ATOMS

Section: &ATOMS

The definition of dummy atoms follows this keyword.
Three different kinds of dummy atoms are implemented. Type 1 is fixed in space, type 2 lies at the arithmetic mean, and type 3 at the center of mass of the coordinates of real atoms.
The first line contains the total number of dummy atoms. The following lines start with the type label TYPE1, TYPE2, TYPE3.
For type 1 dummy atoms the label is followed by the Cartesian coordinates.
For type 2 and type 3 dummy atoms the first number specifies the total number of atoms involved in the definition of the dummy atom. Then the number of these atoms has to be specified on the same line. A negative number of atoms stands for all atoms.
Example:

DUMMY ATOMS
3
TYPE1	0.0	0.0	0.0
TYPE2	2	1	4
TYPE3	-1

ELECTRONIC SPECTRA

Section: &CPMD

Perform a TDDFT calculation [87,88] to determine the electronic spectra. See below under Electronic Spectra and under the other keywords for the input sections &LINRES and &TDDFT for further options.

ELECTROSTATIC POTENTIAL

Section: &CPMD

Store the electrostatic potential on file.

ELF [PARAMETER]

Section: &CPMD

Store the total valence density and the valence electron localization function ELF [48,76,77] on files. The default smoothing parameters for ELF can be changed optionally when specifying in addition the PARAMETER keyword. Then the two parameters ``elfcut'' and ``elfeps'' are read from the next line. The particular form of ELF that is implemented is defined in the header of the subroutine elf.F. Note: it is a very good idea to increase the planewave cutoff and then specify ``elfcut'' $=0.0$ and ``elfeps'' $=0.0$ if you want to obtain a smooth ELF for a given nuclear configuration. In the case of a spin-polarized (i.e. spin unrestricted) DFT calculation (see keyword LSD) in addition the spin-polarized average of ELF as well as the separate $\alpha$- and $\beta$-orbital parts are written to the files LSD_ELF, ELF_ALPHA and ELF_BETA, respectively; see Ref. [49] for definitions and further infos. Note: ELF does not make much sense when using Vanderbilt's ultra-soft pseudopotentials!

EMASS

Section: &CPMD

The fictitious electron mass in atomic units is read from the next line.
Default is 400 a.u..

ENERGY PROFILE

Section: &SYSTEM

Perform an energy profile calculation at the end of a wavefunction optimization using the ROKS or ROSS methods.

ENERGYBANDS

Section: &CPMD

Write the band energies (eigenvalues) for k points in the file ENERGYBANDS.

EPR options, see response_p.inc

Section: &RESP

Calculate the EPR $g$ tensor for the system. This routine accepts most, if not all, of the options available in the NMR routine (RESTART, NOSMOOTH, NOVIRTUAL, PSI0, RHO0, OVERLAP and FULL). Most important new options are:
FULL SMART: does a calculation with improved accuracy. A threshold value (between 0 and 1) must be present on the next line. The higher the threshold value, the lower the computational cost, but this will also reduce the accuracy (a bit). Typically, a value of 0.05 should be fine.
OWNOPT: for the calculation of the $g$ tensor, an effective potential is needed. By default, the EPR routine uses the local potential ( $V_{LOC} = V_{PP,LOC} + V_{HARTREE} + V_{XC}$). This works well with Goedecker pseudopotentials, but rather poor with Troullier-Martins pseudopotentials. When using this option, the following potential is used instead:

$$V_{EFF} = -\frac{Z}{r}\mathrm{erf}(r/r_c) + V_{HARTREE} + V_{XC}$$

and $r_c$ (greater than 0) is read on the next line.
HYP: calculates the hyperfine tensors. See epr_hyp.F for details.

Contact Reinout.Declerck@UGent.be should you require further information.

EXCHANGE CORRELATION TABLE [NO]

Section: &DFT

Specifies the range and the granularity of the lookup table for the local exchange-correlation energy and potential. The number of table entries and the maximum density have to be given on the next line.
Note that this keyword is only relevant when using OLDCODE and even then it is set to NO be default. Previous default values were 30000 and 2.0.

EXCITED DIPOLE

Section: &PROP

Calculate the difference of dipole moments between the ground state density and a density generated by differently occupied Kohn-Sham orbitals.
On the next line the number of dipole moments to calculate and the total number orbitals has to be given. On the following lines the occupation of the states for each calculation has to be given. By default the dipoles are calculated by the method used for the DIPOLE MOMENT option and the same restrictions apply. If the LOCAL DIPOLE option is specified the dipole moment differences are calculated within the same boxes.

EXTERNAL POTENTIAL {ADD}

Section: &CPMD

Read an external potential from file. With ADD specified, its effects is added to the forces acting on the ions.

EXTRAPOLATE WFN

Section: &CPMD

Read the number of wavefunctions to retain from the next line.
These wavefunctions are used to extrapolate the initial guess wavefunction in Born-Oppenheimer MD.

FACMASS

Section: &PIMD

Obtain the fictitious nuclear masses $M_I^\prime$ within path integral molecular dynamics from the real physical atomic masses $M_I$ (as tabulated in the DATA ATWT / .../ statement in atoms.F) by multiplying them with the dimensionless factor WMASS that is read from the following line; if the NORMAL MODES or STAGING propagator is used obtain $M_I^{\prime (s)}=$   WMASS$\cdot M_I^{(s)}$ for all replicas $s=1, \dots , P$; see e.g. Ref. [74] eq. (2.37) for nomenclature.
Default value of WMASS is 1.0

FILE FUSION

Section: &CPMD

Reads in two separate RESTART files for ground state and ROKS excited state and writes them into a single RESTART file. Required to start SURFACE HOPPING.

FILEPATH

Section: &CPMD

The path to the files written by CPMD (RESTART.x, MOVIE, ENERGIES, DENSITY.x etc.) is read from the next line. This overwrites the value given in the environment variable CPMD_FILEPATH. Default is the current directory.

FINITE DIFFERENCES

Section: &CPMD

The step length in a finite difference run for vibrational frequencies (VIBRATIONAL ANALYSIS keywords) is read from the next line.
With the keywords COORD=coord_fdiff(1..3) and RADIUS=radius put in the same line as the step length, you can specify a sphere in order to calculate the finite differences only for the atoms inside it. The sphere is centered on the position coord_fdiff(1..3) with a radius radius (useful for a point defect).

NOTE: The the step length for the finite difference is always in Bohr (default is 1.0d-2 a.u.). The (optional) coordinates of the center and the radius are read in either Angstrom or Bohr, depending on whether the ANGSTROM keyword is specified or not.

FIXRHO UPWFN [VECT LOOP WFTOL]

Section: &CPMD

Wavefunctions optimization with the method of direct inversion of the iterative subspace (DIIS), performed without updating the charge density at each step. When the orbital energy gradients are below the given tolerance or when the maximum number of iterations is reached, the KS energies and the occupation numbers are calculated, the density is updated, and a new wavefunction optimization is started. The variations of the density coefficients are used as convergence criterium. The default electron temperature is 1000 K and 4 unoccupied states are added. Implemented also for k-points. Only one sub-option is allowed per line and the respective parameter is read from the next line. The parameters mean:

VECT:

The number of DIIS vectors is read from the next line. (ODIIS with 4 vectors is the default).

LOOP:

the minimum and maximum number of DIIS iterations per each wfn optimization is read from the following line. Default values are 4 and 20.

WFTOL:

The convergence tolerance for the wfn optimization during the ODIIS is read from the following line. The default value is $10^{-7}$. The program adjusts this criterion automatically, depending on the convergence status of the density. As the density improves (when the density updates become smaller), also the wavefunction convergence criterion is set to its final value.

FORCE FIELD ... END FORCE FIELD

Section: &CLASSIC

FORCE STATE

Section: &TDDFT

The state for which the forces are calculated is read from the next line. Default is for state 1.

FREE ENERGY FUNCTIONAL

Section: &CPMD

Calculates the electronic free energy using free energy density functional [55,56,57] from DFT at finite temperature.
This option needs additional keywords (free energy keywords).
By default we use Lanczos diagonalisation with Trotter factorization and Bogoliubov correction. If the number of states is not specified, use $N_{electrons}/2+4$.

FREEZE QUANTUM

Section: &CLASSIC

Freeze the quantum atoms and performs a classical MD on the others (in QMMM mode only !).

FULL TRAJECTORY

Section: &CLASSIC

Not documented

FUNCTIONAL functionals

Section: &DFT

Single keyword for setting up XC-functionals.
Available functionals are NONE, SONLY, LDA (in PADE form), BONLY, BP, BLYP, XLYP, GGA (=PW91), PBE, REVPBE, HCTH, OPTX, OLYP, TPSS, PBE0, B1LYP, B3LYP, X3LYP

GC-CUTOFF

Section: &DFT

On the next line the density cutoff for the calculation of the gradient correction has to be specified. The default value is $10^{-8}$. Experience showed that for a small CUTOFF value (e.g. when using Vanderbilt pseudopotentials) a bigger values have to be used. A reasonable value for a 25 ryd cutoff calculation is $5 \cdot 10^{-6}$.
Warning: for the HCTH functional, since it includes both the $xc$ part and the gradient correction in a unique functional, a GC-CUTOFF too high (e.g. $\geq 5 \cdot 10^{-5}$) could result in not including any $xc$ part with uncontrolled related consequences.

GDIIS

Section: &CPMD

Use the method of direct inversion in the iterative subspace combined with a quasi-Newton method (using BFGS) for optimization of the ionic positions [25].The number of DIIS vectors is read from the next line.
GDIIS with 5 vectors is the default method in optimization runs.

GENERATE COORDINATES

Section: &ATOMS

The number of generator atoms for each species are read from the next line.
These atoms are used together with the point group information to generate all other atomic positions. The input still has to have entries for all atoms but their coordinates are overwritten. Also the total number of atoms per species has to be correct.

GENERATE REPLICAS

Section: &PIMD

Generate quantum free particle replicas from scratch given a classical input configuration according to the keyword DEBROGLIE specification. This is the default if INITIALIZATION is active.

GRADIENT CORRECTION [functionals]

Section: &DFT

Individual components of gradient corrected functionals can be selected. Rarely needed anymore, use the FUNCTIONAL keyword instead.

Functionals implemented are for the exchange energy:
BECKE88 [31], GGAX [35] PBEX [36], REVPBEX [37], HCTH [38], OPTX [39]
and for the correlation part:
PERDEW86 [33], LYP [30], GGAC [35], PBEC [36], REVPBEC [37], HCTH [38] OLYP [39].
Note that for HCTH, exchange and correlation are treated as a unique functional.
The keywords EXCHANGE and CORRELATION can be used for the default functionals (currently BECKE88 and PERDEW86). If no functionals are specified the default functionals for exchange and correlation are used.

GSHELL

Section: &CPMD

Write a file GSHELL with the information on the plane waves for further use in S(q) calculations.

HAMILTONIAN CUTOFF

Section: &CPMD

The lower cutoff for the diagonal approximation to the Kohn-Sham matrix [5] is read from the next line.
Default is 0.5 atomic units.
For variable cell dynamics only the kinetic energy as calculated for the reference cell is used.

HAMILTONIAN CUTOFF

Section: &RESP

The value where the preconditioner (the approximate Greens function $(V_{kin}+V_{coul}-\epsilon_{KS})^{-1})$ is truncated. HTHRS can also be used. Default value is 0.5.

HARMONIC REFERENCE SYSTEM [OFF]

Section: &CPMD

Switches harmonic reference system integration [5] on/off.
The number of shells included in the analytic integration is controlled with the keyword HAMILTONIAN CUTOFF.
By default this option is switched off.

HARTREE-FOCK

Section: &DFT

Do a Hartree-Fock calculation. This only works correctly for isolated systems. It should be used with care, it needs enormous amounts of CPU time.

HARTREE

Section: &DFT

Do a Hartree calculation. Only of use for testing purposes.

HESSCORE

Section: &CPMD

Calculates the partial Hessian after relaxation of the enviroment, equivalent to NSMAXP=0 (PRFO NSMAXP).

HESSIAN [DISCO,SCHLEGEL,UNIT,PARTIAL]

Section: &CPMD

The initial approximate Hessian for a geometry optimization is constructed using empirical rules with the DISCO [24] or Schlegel's [16] parametrization or simply a unit matrix is used.
If the option PARTIAL is used the initial approximate Hessian for a geometry optimization is constructed from a block matrix formed of the parametrized Hessian and the partial Hessian (of the reaction core). If the reaction core spans the entire system, its Hessian is simply copied. The keywords RESTART PHESS are required.

HFX CUTOFF

Section: &SYSTEM

Set an additional cutoff for wavefunctionand density to be used in the calculation of exact exchange. Cutoffs for wavefunctions and densities are read from the next line in Rydberg units. Defaults are the same cutoffs as for the normal calculation. Only lower cutoffs than the defaults can be specified.

HTHRS

Section: &LINRES

Threshold for Hessian in preconditioner for linear response optimizations. Default is 0.5.

IMPLICIT NEWTON RAPHSON {PREC, CONTINUE, VERBOSE, ALTERNATIVE, STEP} [N=nreg]

Section: &CPMD

Not documented.

INITIALIZATION

Section: &PIMD

Provide an initial configuration for all replicas as specified either by GENERATE REPLICAS or by READ REPLICAS. This option is automatically activated if RESTART COORDINATES is not specified. It is defaulted to GENERATE REPLICAS together with DEBROGLIE CENTROID and a temperature of 500 Kelvin.

INITIALIZE WAVEFUNCTION [RANDOM, ATOMS]

Section: &CPMD

The initial guess for wavefunction optimization are either random functions or functions derived from the atomic pseudo-wavefunctions.
Default is to use the atomic pseudo-wavefunctions.

INTERFACE {EGO,GMX} {[MULLIKEN, LOWDIN, ESP, HIRSHFELD],PCGFIRST}

Section: &CPMD

Use CPMD together with a classical molecular dynamics code. CPMD and the classical MD code are run simultaneously and communicate via a file based protocol. See the file egointer.F for more details. This needs a specially adapted version of the respective classical MD code. So far, there is an interface[91,93] to the MD programs ego[89,90] and Gromacs[92].

When using the suboption PCGFIRST the code will use PCG MINIMIZE on the very first wavefunction optimization and then switch back to DIIS.

INTFILE [READ,WRITE,FILENAME]

Section: &CPMD

Not documented

ISOLATED MOLECULE

Section: &CPMD

Calculate the ionic temperature assuming that the system consists of an isolated molecule or cluster.
Note: This keyword affects exclusively the determination of the number of dynamical degrees of freedom. This keyword does not activate the 'cluster option' SYMMETRY 0, but it is activated if SYMMETRY 0 is used unless the keyword QMMM is set as well. It allows studying an isolated molecule or cluster within periodic boundary conditions.

ISOTOPE

Section: &ATOMS

Changes the default masses of the atoms.
This keyword has to be followed by NSP lines (number of atom types). In each line the new mass (in a.m.u.) of the respective species has to be specified (in order of their definition).

ISOTROPIC CELL

Section: &SYSTEM

Specifies a constraint on the super cell in constant pressure dynamics or geometry optimization. The shape of the cell is held fixed, only the volume changes.

KEEPREALSPACE

Section: &RESP

Like the standard CPMD option, this keeps the C0 ground state wavefunctions in the direct space representation during the calculation. Can save a lot of time, but is incredibly memory intensive.

KOHN-SHAM ENERGIES [OFF,NOWAVEFUNCTION]

Section: &CPMD

Calculation of the Kohn-Sham energies and the corresponding orbitals.
The number of empty states that have to be calculated in addition to the occupied states is read from the next line.
The Kohn-Sham orbitals are stored on the file RESTART.x except if the keyword NOWAVEFUNCTION is used. In this case, the program does not allocate memory for wavefunctions for all k points. It computes eigenvalues k point per k point losing information about wavefunctions. This keyword is used for band structure calculation to compute the eigenvalues for many k points.
Default is not to calculate Kohn-Sham energies (OFF ).
Warning: The usage of this keyword needs special care (especially restarts).

KPERT [MONKHORSTPACK,SCALE]

Section: &RESP

Calculation of total energy and electronic density of states with an arbitraty number of k-points (at almost no additional computational effort). The method is based on a ${\bf k}\cdot {\bf p}-$like approximation developed in the framework of the density functional perturbation theory [99]. For a sampling of the BZ determined by the Monkhorst-Pack algorithm, the option MONKHORSTPACK has to be specified, followed by the dimension of the mesh along the 3 reciprocal space axis $(NK_{1} , NK_{2} , NK_{3})$. If omitted, the individual absolute coordinates of the k-points have to be given one by one in the following lines. The SCALE option allows to specify them in units of the reciprocal cell vectors.

The line after KPERT has to contain the the total number of k-points $(NKPTS)$, which have then to be given by their coordinates and the associated weights $(RK,WK)$ in the format:
$NKPTS$
$RK_{x1} \; RK_{y1} \; RK_{z1} \; WK_{1}$
$\dots$
$RK_{x NKPTS} \; RK_{y NKPTS} \; RK_{z NKPTS} \; WK_{NKPTS}$.
Three response wavefunctions are calculated, corresponding to the three independent orientations of the k basis vectors in reciprocal space. Therefore, 3 independent optimization loops are started ($x,y$ and $z$), and the 3 sets of wfns are stored (you need 4 times the memory required for a standard wavefunction optimization). The second order correction to the $\Gamma$-point total energy is calculated for the requested k-point mesh.

Further options are (each in a new line of the input file ):

WRITE_C1

the 3 sets of response wfns are stored in three separate restart files.

HAMILTONIAN

the k-dependent Hamiltonian is constructed via the second order perturbation theory approximation, and the corresponding KS energies are calculated. Due to technical reasons, for each k-point $2*NSTATE$ KS energies are calculated, however only those corresponding to occupied orbitals are reliable.

READ_C1

the response wfns are read from RESTART.P_{xyz}.

BUILD_C00

the set of k-dependent wfns (first order correction) is calculated from the unperturbed $\Gamma$-point wfns together with the response orbitals. They are then written in a standard RESTART file. From this RESTART file one can perform a calculation of the Hamiltonian matrix for each kpoint and calculate the KS energies (use LANCZOS DIAGO in &CPMD and the KPOINT option ONLYDIAG in &SYSTEM. The k-point mesh must be the same used in the linear response calculation. set also NOSPHERICAL CUTOFF in &SYSTEM).

NORESTART

no RESTART file is written.

KPOINTS options

Section: &SYSTEM

With no option, read in the next line with the number of k-points and for each k-point, read the components in the Cartesian coordinates (units $2\pi/a$) and the weight.

MONKHORST-PACK

Read in the next line three numbers for the Monkhorst-Pack mesh. The program calculates then the special k-points. With the keyword SHIFT=kx ky kz in the same line, you can precise the constant vector shift.

SYMMETRIZED

Symmetrized special k-points mesh (useful if you use a constant vector shift).

FULL

Construct full Monkhorst-Pack mesh with only inversion symmetry. Useful for molecular dynamics simulation The keywords SYMMETRIZED FULL preserves all symmetry of Bravais lattice so there is no need to symmetrize density and forces.

SCALED

You can give k-points in reciprocal space coordinates.

BANDS

This option is to calculate the band structure.
For each line you have to specify the number of k-points for the band, the initial and the final k-point. To finish the input, put:
0 0. 0. 0. 0. 0. 0.

BLOCK=n [OPTIONS]

The block option, specifies the number of k-points in the memory. The program uses a swap file to store the wavefunctions only by default. With the following options, you can change this behaviour:

ALL

Three swap files are used to store wavefunctions and others arrays related to k-points. Swap files are in the current directory or the temporary directory given by environment variable TMPDIR. The use of memory is smaller than with the above option.

CALCULATED

One swap file is used to store only wavefunctions. The other arrays related to k-points are calculated each time if needed.

NOSWAP

The wavefunctions are not swapped. This is useful to calculate eigenvalues for each k point with few memory used.
Warning: The wavefunctions calculated are irrelevant. You have to specify explicitly some other options to use it:
MAXSTEP 1 and
STORE OFF WAVEFUNCTIONS DENSITY POTENTIAL.

LANCZOS DIAGONALISATION {ALL}

Section: &CPMD

Use Lanczos diagonalisation scheme.
Default with free energy functional.

LANCZOS DIAGONALISATION {OPT,RESET=n}

Section: &CPMD

Use Lanczos diagonalisation scheme after (OPT) or periodically during (RESET=n) direct wavefunction optimization using ODIIS. The number n specifies the number of DIIS resets (ODIIS NO_RESET=nreset) due to poor progress until the wavefunction is diagonalized. This can be helpful if the wavefunction is converging very slowly.

LANCZOS PARAMETER [N=n] [ALL]

Section: &CPMD

Give four parameters for Lanczos diagonalisation in the next line:

• Maximal number of Lanczos iterations (50 is enough),
• Maximal number for the Krylov sub-space (8 best value),
• Blocking dimension ( $\le NSTATE$, best in range 20-100) If you put a negative or zero number, this parameter is fixed by the program in function of the number of states ( $(n+1)/(int(n/100+1))$).
• Tolerance for the accuracy of wavefunctions
  ($10^{-8}$ otherwise $10^{-12}$ with Trotter approximation)

If n is specified, read $n-1$ lines after the first one, containing a threshold density and a tolerance. See the hints section 9.12.1 for more information.

LANCZOS [CONTINUE,DETAILS]

Section: &RESP

lanczos_dim iterations conv_threshold lanczos_dim= dimension of the vibrational d.o.f. iterations = no. of iterations desired for this run conv_threshold = threshold for convergence on eigenvectors CONTINUE = argument for continuing Lanczos diagonalization from a previous run (reads file LANCZOS_CONTINUE) DETAILS = argument for verbosity. prints a lot of stuff

LBFGS [NREM, NTRUST, NRESTT, TRUSTR]

Section: &CPMD

Use the limited-memory BFGS method (L-BFGS) for linear scaling optimization of the ionic positions. For more informations, see [10]. The information about the Hessian for the quasi-Newton method employed is derived from the history of the optimization [10,11].
Only one sub-option is allowed per line and the respective parameter is read from the next line. The parameters mean:

NREM:

Number of ionic gradients and displacements remembered to approximate the Hessian. The default is either 40 or the number of ionic degrees of freedom, whichever is smaller. Values greater the number of degrees of freedom are not advisable.

NTRUST:

NTRUST=1 switches from a trust radius algorithm to a line search algorithm. The default value of 0 (trust radius) is recommended.

NRESTT:

NRESTT$>$0 demands a periodic reset of the optimizer every NRESTT steps. Default is 0 (no periodic reset). This option makes only sense if the ionic gradient is not accurate.

TRUSTR:

Maximum and initial trust radius. Default is 0.5 atomic units.

It can be useful to combine these keywords with the keywords PRFO, CONVERGENCE ADAPT, RESTART LSSTAT, PRINT LSCAL ON and others.

LDA CORRELATION [functional]

Section: &DFT

The LDA correlation functional is specified.
Possible functionals are NO (no correlation functional), PZ [32], VWN [29], LYP [30] and PW [34].
Default is the PZ, the Perdew and Zunger fit to the data of Ceperley and Alder [28].

LDOS

Section: &PROP

Calculate the layer projected density of states. The number of layers is read from the next line.

To use the LDOS keyword, the user must first have performed a wavefunction optimization and then restart with with the PROPERTIES and LANCZOS DIAGONALISATION keywords in the &CPMD section (and LDOS in the &PROP section).

Warning: If you use special k-points for a special structure you need to symmetrize charge density for which you must specify the POINT GROUP.

LINEAR RESPONSE

Section: &CPMD

A perturbation theory calculation is done, according to the (required) further input in the &RESP section. In the latter, one of the possible perturbation types (PHONONS, LANCZOS, RAMAN, FUKUI, KPERT, NMR, EPR, see section 9.9.2) can be chosen, accompagnied by further options.

LOCAL DIPOLE

Section: &PROP

Calculate $numloc$ local dipole moments.
$numloc$ is read from the next line followed by two numloc lines with the format:
$xmin$ $ymin$ $zmin$
$xmax$ $ymax$ $zmax$

LOCALIZATION

Section: &TDDFT

Use localized orbitals in the TDDFT calculation. Default is to use canonical orbitals.

LOCALIZE

Section: &HARDNESS

Use localized orbitals in an orbital hardness calculation

LOCALIZE

Section: &PROP

Localize the molecular orbitals as defined through the atomic basis set.
The same localization transformation is then applied also to the wavefunctions in the plane wave basis. These wavefunction can be printed with the keyword RHOOUT specified in the section &CPMD ... &END.

LR KERNEL functional

Section: &DFT

Use another functional for the linear response kernel.

LR-TDDFT

Section: &TDDFT

Use full linear response version of TDDFT. Default is to use TAMM-DANCOFF approximation.

LSD

Section: &CPMD

Use the local spin density approximation.
Warning: Not all functionals are implemented for this option.

LOCAL SPIN DENSITY

Section: &CPMD

Use the local spin density approximation.
Warning: Not all functionals are implemented for this option.

LOW SPIN EXCITATION [ROKS,ROSS,ROOTHAAN,CAS22]

Section: &SYSTEM

Use the low spin excited state functional [65].

LSE PARAMETERS

Section: &SYSTEM

Only for LSE experts, see code.

MAXCPUTIME

Section: &CPMD

The maximum CPU TIME to be used is read from the next line.
Default is no limit.

MAXITER

Section: &CPMD

The maximum number of iterations for the self-consistency for wavefunctions, geometry optimization or conventional molecular dynamics to be performed. The value is read from the next line.
Default is 10000 steps.

MAXSTEP

Section: &CPMD

The maximum number of steps for wavefunction, geometry optimization or molecular dynamics to be performed. The value is read from the next line.
Default is 10000 steps.

MAXSTEP

Section: &LINRES

Maximum number of optimization steps for linear response optimizations. Default is 1000.

MEMORY {SMALL, BIG}

Section: &CPMD

Using BIG, the structure factors for the density cutoff are only calculated once and stored for reuse.
This option allows for considerable time savings in connection with Vanderbilt pseudopotentials.
Default is (SMALL) to recalculate them whenever needed.

MESH

Section: &SYSTEM

The number of real space mesh points in $x-$, $y-$ and $z-$direction is read from the next line.
If the values provided by the user are not compatible with the plane-wave cutoff or the requirements of the FFT routines the program chooses the next bigger valid numbers.
Default are the minimal values compatible with the energy cutoff and the FFT requirements.

METADYNAMICS ... END METADYNAMICS

Section: &ATOMS

Initiate Metadynamics (see section 9.10 for more information on the available options and the input format).

MIRROR

Section: &CPMD

Write the input file to the output.

MIXDIIS

Section: &CPMD

Not documented

MIXSD

Section: &CPMD

Not documented

MODIFIED GOEDECKER [PARAMETERS]

Section: &CPMD

To be used in combination with LOW SPIN EXCITATION ROKS.
Calculation of the off-diagonal Kohn-Sham matrix elements $F_{AB}$ and $F_{BA}$ (with A, B: ROKS-SOMOs) is performed according to a modified Goedecker-Umrigar scheme ( $F_{AB} := (1-\lambda _{AB})F_{AB} + \lambda _{AB} F_{BA}$ and $F_{BA} := (1-\lambda _{BA})F_{BA} + \lambda _{BA} F_{AB}$ ). Default values are $\lambda _{AB}=-0.5$ and $\lambda _{BA}=0.5$. see Ref. [66].

With the optional keyword PARAMETERS: $\lambda _{AB}$ and $\lambda _{BA}$ are read from the next line. Can be used to avoid unphysical rotation of the SOMOs. Always check the orbitals!

MOLECULAR DYNAMICS [CP, BO, PT, CLASSICAL]

Section: &CPMD

Perform a molecular dynamics (MD) run. CP stands for a Car-Parrinello type MD. With the option BO a Born-Oppenheimer MD is performed where the wavefunction is reconverged after each MD-step. CLASSICAL means that a MD that includes classical atoms is performed. Default is CP.

MOLECULAR STATES

Section: &TDDFT

Calculate and group Kohn-Sham orbitals into molecular states for a TDDFT calculation.

MOVERHO

Section: &CPMD

Mixing used during optimization of geometry or molecular dynamics. Use atomic or pseudowavefunctions to project wavefunctions in order to calculate the new ones with movement of atoms. Read in the next line the parameter (typically 0.2).

MOVIE TYPE

Section: &ATOMS

Assign special movie atom types to the species.
The types are read from the next line. Values from 0 to 5 were allowed in the original MOVIE format.

MOVIE [OFF, SAMPLE]

Section: &CPMD

Write the atomic coordinates without applying periodic boundary conditions in MOVIE format every IMOVIE time steps on file MOVIE. IMOVIE is read from the next line.
Default is not to write a movie file.

MULTIPLICITY

Section: &SYSTEM

This keyword only applies to LSD calculations.
The multiplicity (2$S$+1) is read from the next line.
Default is the smallest possible multiplicity.

NEWCODE

Section: &DFT

Switch to select one out of two versions of code to calculate exchange-correlation functionals.
NEWCODE is the default, but not all functionals are available with NEWCODE, if you select one of these, OLDCODE is used automatically. NEWCODE is highly recommended for all new projects and especially for vector computers, also some of the newer functionality is untested or non-functional with OLDCODE.

NMR options, see response_p.inc

Section: &RESP

Calculate the NMR chemical shielding tensors for the system. Most important option: FULL, does a calculation with improved accuracy for periodic systems but takes a lot of time. Isolated systems: Use OVERLAP and 0.1 (on next line) for the same effect. Be careful for non-hydrogen nuclei. The shielding is calculated without contribution from the core electrons. Contact sebastia@mpip-mainz.mpg.de for further details.

NOGEOCHECK

Section: &CPMD

Default is to check all atomic distances and stop the program if the smallest disctance is below 0.5 Bohr. This keyword requests not to perform the check.

NONORTHOGONAL ORBITALS [OFF]

Section: &CPMD

Use the norm constraint method [7] for molecular dynamics or nonorthogonal orbitals in an optimization run.
On the next line the limit of the off diagonal elements of the overlap matrix is defined. Warning: Adding or deleting this option during a MD run needs special care.

NOOPT

Section: &RESP

Do not perform a ground state wfn optimization. Be sure the restarted wfn is at the BO-surface.

NOPRINT ORBITALS

Section: &PROP

Do not print the wavefunctions in the atomic basis set.

NORMAL MODES

Section: &PIMD

Use the normal mode representation [61] of the path integral propagator. It is possible to impose a mass disparity between centroid and non-centroid coordinates by dividing the fictitious masses of only the non-centroid $s=2, \dots ,P$ replicas by the adiabaticity control factor FACSTAGE. This dimensionless factor must always be specified in the following line. Note: the eigen-frequencies of the $s>1$ replicas are changed by only $\sqrt{\mbox{FACSTAGE}}$, see Ref. [63](b). Using FACSTAGE $\not= 1.0$ makes only sense in conjunction with CENTROID DYNAMICS where WMASS=1.0 has to be used as well.

NOSE PARAMETERS

Section: &CPMD

The parameters controlling the Nosé thermostats are read in the following order from the next line:
The length of the Nosé-Hoover chain for the ions,
the length of the Nosé-Hoover chain for the electrons,
the length of the Nosé-Hoover chain for the cell parameters.
(The respective default values are 4.)
The multiplication factor (NEDOF0, a real number) for the number of electronic degrees of freedom. The used degrees of freedom (NEDOF) are defined as $NEDOF=NEDOF0*X$ If NEDOF0 is a negative number X is the true number of DOFs, if it's a positive number, X is the number of electronic states (default for NEDOF0 is 6).
The order of the Suzuki/Yoshida integrator (default is 7, choices are 3, 5, 7, 9, 15, 25, 125 and 625),
and the decomposition ratio of the time step (default is 1).
If this keyword is omitted, the defaults are used.
If the keyword is used all parameters have to be specified.

NOSE {IONS, ELECTRONS, CELL} [ULTRA,MASSIVE,CAFES]

Section: &CPMD

Nosé-Hoover chains [14,15] for the ions, electrons, or cell parameters are used.
The target temperature in Kelvin and the thermostat frequency in $cm^{-1}$, respectively the fictitious kinetic energy in atomic units and the thermostat frequency in $cm^{-1}$ are read from the next line. For the ionic case the additional keyword ULTRA selects a thermostat for each species, the keyword MASSIVE selects a thermostat for each degree of freedom, and the keyword CAFES can be used to give different temperatures to different groups of atoms[20]. The syntax in the CAFES case is:


NOSE IONS CAFES
    ncafesgrp
  cpnumber_a_1  cpnumber_a_2  Temperature Frequency
...
  cpnumber_n_1  cpnumber_n_2  Temperature Frequency


There are ncafesgrp groups, specified by giving their first CPMD atom number (cpnumber_X_1) and last CPMD atom number (cpnumber_X_2). In the case of hybrid QM/MM simulations, you have to consult the QMMM_ORDER file to find those numbers. The temperature and frequency can be different for each group. All atoms of the system have to be in a CAFES group. A new file, CAFES is created containing the temperature of each group (cols. 2 ...ncafesgrp+1) and the energy of the Nose-Hoover chains of that group (last columns).
Using CAFES with different temperatures only makes sense if the different groups are decoupled from each other by increasing the masses of the involved atoms. The mass can be specified in the topology / or with the ISOTOPE keyword. However, you can only change the mass of a complete CPMD species at a time. Hence, the topology and/or the input should be such that atoms of different CAFES group are in different species.
NOTE: CAFES is currently not restartable.

OCCUPATION [FIXED]

Section: &SYSTEM

The occupation numbers are read from the next line.
This keyword must be preceeded by STATES. The FIXED option fixes the occupation numbers for the diagonalisation scheme, otherwise this option is meaningless.

ODIIS [NOPRECONDITIONING,NO_RESET=nreset]

Section: &CPMD

Use the method of direct inversion in the iterative subspace for optimization of the wavefunction [8].
The number of DIIS vectors is read from the next line.
(ODIIS with 10 vectors is the default method in optimization runs.)
The preconditioning is controlled by the keyword HAMILTONIAN CUTOFF. Optionally preconditioning can be disabled.
By default, the number of wavefunction optimization cycles until DIIS is reset on poor progress, is the number of DIIS vectors. With ODIIS NO_RESET, this number can be changed, or DIIS resets can be disabled altogether with a value of -1.

OLDCODE

Section: &DFT

see NEWCODE

OPTIMIZE SLATER EXPONENTS

Section: &PROP

Not documented

OPTIMIZER [SD,DIIS,PCG,AUTO]

Section: &LINRES

Optimizer to be used for linear response equations. Default is ``AUTO'' which will first use PCG, then switch to DIIS and finally switch to DIIS with full storage and state dependent preconditioner. THAUTO sets the two tolerances for when to do the switch.

OPTIMIZE {GEOMETRY [XYZ, SAMPLE], WAVEFUNCTION, COMBINED}

Section: &CPMD

GEOMETRY causes the program to optimize the geometry and the wavefunction of the system. The keyword XYZ writes the geometry additionally in xyz-format every NGXYZ step on the file GEO_OPT.xyz. If the keyword SAMPLE is given NGXYZ is read from the next line, the default value for NGXYZ is $1$.
Using WAVEFUNCTION only the wavefunction is optimized.
For cell optimizations refer to the STEEPEST DESCENT CELL keyword. COMBINED stands for a molecular dynamics based geometry optimization method. This method is not yet fully operational in the current version.

ORBITAL HARDNESS [LR,FD]

Section: &CPMD

Perform an orbital hardness calculation. See section &Hardness for further input options.

ORBITALS

Section: &HARDNESS

Specify the number of orbitals to be used in a hardness calculation on the next line.

ORTHOGONALIZATION {LOWDIN, GRAM-SCHMIDT}

Section: &CPMD

Orthogonalization in optimization runs is done either by a Löwdin (symmetric) or Gram-Schmidt procedure.
Default is Gram-Schmidt except for parallel runs where Löwdin orthogonalization is used with the conjugate-gradient scheme.

OUTPUT [ALL, GROUPS, PARENT]

Section: &PIMD

Output files for each processor, processor group, or only grandparent. Default is PARENT to standard output file (Note: some information such as messages for correct reading / writing of restart files is lost); GROUPS and ALL write to the files OUTPUT_$n$ where $n$ is the group and bead number, respectively.

PARRINELLO-RAHMAN {NPT}

Section: &CPMD

To be used together with MOLECULAR DYNAMICS.
A variable cell MD with the Parrinello-Rahman Lagrangian is performed. With the additional keyword a constant NPT MD using the method of Martyna, Tobias, and Klein [52].
If this keyword is used together with other run options like OPTIMIZE WAVEFUNCTIONS, calculations with different reference cells can be performed.

PATH INTEGRAL

Section: &CPMD

Perform a path integral molecular dynamics calculation [58,59].
This keyword requires further input in the section &PIMD ... &END.

PATH SAMPLING

Section: &CPMD

Use CPMD together with a reaction path sampling [86] program. This needs special software. Note: this keyword has nothing to do with path integral MD as activated by the keyword PATH INTEGRAL and as specified in the section &PIMD ... &END.

PCG PARAMETER

Section: &TDDFT

The parameters for the PCG diagonalization are read from the next line. If MINIMIZE was used in the DIAGONALIZER then the total number of steps (default 100) and the convergence criteria (default $10^{-8}$) are read from the next line. Without minimization in addition the step length (default 0.5) has also to be given.

PCG [MINIMIZE,NOPRECONDITIONING]

Section: &CPMD

Use the method of preconditioned conjugate gradients for optimization of the wavefunction.
The fixed step length is controlled by the keywords TIMESTEP and EMASS.
If option MINIMIZE is chosen then line searches are performed.
The preconditioning is controlled by the keyword HAMILTONIAN CUTOFF. Optionally preconditioning can be disabled.

PHONON

Section: &RESP

Calculate the harmonic frequencies from perturbation theory.

POINT GROUP [MOLECULE], [AUTO], [DELTA=delta]

Section: &SYSTEM

The point group symmetry of the system can be specified in the next line. With the keyword AUTO in the next line, the space group is determined automatically. This affects the calculation of nuclear forces and ionic positions. The electronic density and nuclear forces are symmetrized in function of point group symmetry. The group number is read from the next line.
Crystal symmetry groups:

               1  1 (c1)     9   3m (c3v)   17 4/mmm (d4h)   25  222 (d2)
               2 <1>(ci)    10  <3>m(d3d)   18   6   (c6)    26  mm2 (c2v)
               3  2 (c2)    11   4  (c4)    19  <6>  (c3h)   27  mmm (d2h)
               4  m (c1h)   12  <4> (s4)    20   6/m (c6h)   28  23  (t)
               5 2/m(c2h)   13  4/m (c4h)   21   622 (d6)    29  m3  (th)
               6  3 (c3)    14  422 (d4)    22   6mm (c6v)   30  432 (o)
               7 <3>(c3i)   15  4mm (c4v)   23  <6>m2(d3h)   31 <4>3m(td)
               8 32 (d3)    16 <4>2m(d2d)   24  6/mmm(d6h)   32  m3m (oh)

You can specify the point group by its name using the keyword NAME= followed by the name of the point group (one of both notations).
For molecular point groups the additional keyword MOLECULE has to be