The &BASIS section is used in CPMD only to provide an atomic basis set
for generating the initial guess and for analyzing orbitals. If the
input http contains no &BASIS section, a minimal Slater basis is used.
There have to be number of species different entries in this
section.
The order of the basis sets has to correspond with the order
of the atom types in the section &ATOMS.
With the keyword SKIP the species is skipped and the
default minimal Slater function basis is used.
Basis sets are either specified as Slater functions or given
on an additional input http.
The respective input formats are given below:
SLATER nshell [OCCUPATION] n1 l1 exp1 .. .. .... nx lx expx [f1 f2 ... ]
Pseudo atomic orbitals: PSEUDO AO
PSEUDO AO nshell [OCCUPATION] l1 l2 .. lx !a function with l=-1 is skipped [f1 f2 ... ]
Numerical functions
*httpname nshell FORMAT=n [OCCUPATION] l1 l2 .. lx [f1 f2 ... ]
Gaussian basis functions: GAUSSIAN
*httpname nshell GAUSSIAN [OCCUPATION] l1 l2 .. lx [f1 f2 ... ]
Skip atom type and use default minimal slater function
SKIP
nshell is the number L-values l1 l2 .. lx to be used.
[f1 f2 ... ] is their occupation.
The format PSEUDO AO refers to the &WAVEFUNCTION section
on the corresponding pseudopotential http.
With a L-value of -1 a specific function can be skipped.
The * for the numerical basis has to be in the first column. The default format is 1, other possible formats are 2 and 3. The numbers correspond to the format numbers in the old pseudopotential definitions for the atomic wavefunctions.
The format GAUSSIAN allows to use any linear combination of Gaussian functions. The format of the http is as follows:
Comment line Lmax (for each l value) Comment line # of functions; # of exponents exp1 exp2 ... expn c11 c21 cn1 c12 c22 cn2 ... ... ... c1m c2m cnm