[CPMD-list] Geometry Optimization of H2O and O2
Axel Kohlmeyer
axel.kohlmeyer at theochem.ruhr-uni-bochum.de
Mon Apr 19 13:30:40 CEST 2004
>>> "JB" == Brian Jerry <jb811713 at hotmail.com> writes:
JB> hi,
hi!
JB> I am a new CPMD user. I am trying to do a simple test of optimizing the
JB> geometry of 2 water moleculars and 1 Oxygen molecular. Got some trouble with
JB> convergence. Any suggestion?
your system is most likely not very close to equilibrium,
which may cause some trouble (at least with the vanderbilt
pseudopotentials, which you are using).
you could loosen the initial wavefunction convergence parameter to,
say, 5.0e-4, do several optimization steps, and then increase
the convergence. there also is the
CONVERGENCE ADAPT keyword, that should do something
similar atomatically, e.g. with
CONVERGENCE ADAPT
0.02
CONVERGENCE INITIAL
5.0e-4
CONVERGENCE ORBITALS
1.0e-6
CONVERGENCE GEOMETRY
1.0e-5
but there are some more things to remark about
you input file:
- an oxygen molecule is a triplett in ground state, IIRC,
so you would have to do some kind of open shell calculation,
e.g. with LSD and specify the correct multiplicity.
- your pseudopotentials are not consistent with the
functional you chose. you should recreate them
for blyp.
- a wavefunction energy cutoff of 20-30 rydberg should do.
hope this helps,
axel kohlmeyer.
JB> Thanks.
JB> Jerry
JB> --- My input file ---
JB> &CPMD
JB> OPTIMIZE GEOMETRY
JB> PCG MINIMIZE
JB> TIMESTEP
JB> 20
JB> MEMORY BIG
JB> CONVERGENCE
JB> 1.0e-4 1.0e-4
JB> SPLINE POINTS
JB> 1001
JB> &END
JB> &DFT
JB> NEWCODE
JB> EXCHANGE CORRELATION TABLE NO
JB> FUNCTIONAL BLYP
JB> GC-CUTOFF
JB> 5.0e-6
JB> &END
JB> &SYSTEM
JB> ANGSTROM
JB> SYMMETRY
JB> 1
JB> CHARGE
JB> 0.0
JB> CELL
JB> 6.3 1.0 1.0 0.0 0.0 0.0
JB> CUTOFF
JB> 50.0
JB> &END
JB> &ATOMS
JB> ATOMIC CHARGES
JB> -0.6
JB> 0.3
JB> *008-O-ca--vgrp.uspp NEWF BINARY
JB> LMAX=P
JB> 4
JB> 2.6518 -1.5714 -0.1309
JB> -3.8442 0.5428 -2.4979
JB> 0.7327 -4.2440 2.1886
JB> 0.8347 -4.7227 3.3691
JB> *001-H-gpw--campos.uspp NEWF BINARY
JB> LMAX=S
JB> 4
JB> 2.6813 -2.5699 -0.0836
JB> 3.5705 -1.2189 -0.3089
JB> -3.5930 -0.0389 -3.2716
JB> -3.0803 1.1482 -2.2743
JB> &END
JB> --- Output file ---
JB> ================================================================
JB> = GEOMETRY OPTIMIZATION =
JB> ================================================================
JB> NFI GEMAX CNORM ETOT DETOT TCPU
JB> EWALD SUM IN REAL SPACE OVER 1* 1* 1 CELLS
JB> LINE SEARCH : LAMBDA=.781 ENERGY = -60.550228
JB> 1 4.678E-01 4.831E-02 -57.103813 -5.710E+01 8.89
JB> LINE SEARCH : LAMBDA=.885 ENERGY = -64.501797
JB> 2 1.280E-01 2.781E-02 -61.868566 -4.765E+00 8.70
JB> LINE SEARCH : LAMBDA=.735 ENERGY = -65.196588
JB> 3 1.283E-01 1.030E-02 -64.635310 -2.767E+00 8.24
JB> LINE SEARCH : LAMBDA=.499 ENERGY = -65.671394
JB> 4 1.212E-01 1.101E-02 -65.280482 -6.452E-01 8.23
JB> LINE SEARCH : LAMBDA=.725 ENERGY = -65.831191
JB> 5 5.397E-02 4.565E-03 -65.671525 -3.910E-01 8.26
JB> LINE SEARCH : LAMBDA=.576 ENERGY = -65.912395
JB> 6 3.951E-02 3.628E-03 -65.837318 -1.658E-01 8.61
JB> LINE SEARCH : LAMBDA=.783 ENERGY = -65.969933
JB> 7 2.828E-02 2.348E-03 -65.917186 -7.987E-02 8.67
JB> LINE SEARCH : LAMBDA=.683 ENERGY = -65.998637
JB> 8 2.252E-02 1.583E-03 -65.970402 -5.322E-02 8.17
JB> LINE SEARCH : LAMBDA=.745 ENERGY = -66.023312
JB> 9 1.678E-02 1.625E-03 -65.999339 -2.894E-02 8.24
JB> LINE SEARCH : LAMBDA=.940 ENERGY = -66.045945
JB> ................................................................................................
JB> ................................................................................................
JB> ................................................................................................
JB> 2925 1.695E-04 4.941E-05 -66.451406 0.000E+00 10.18
JB> LINE SEARCH : LAMBDA=.258-307 ENERGY = -66.451406
JB> 2926 1.695E-04 4.941E-05 -66.451406 0.000E+00 10.45
JB> LINE SEARCH : LAMBDA=.581-307 ENERGY = -66.451406
JB> 2927 1.695E-04 4.941E-05 -66.451406 1.421E-14 10.27
JB> LINE SEARCH : LAMBDA=.484-309 ENERGY = -66.451406
JB> 2928 1.695E-04 4.941E-05 -66.451406 -1.421E-14 10.04
JB> LINE SEARCH : LAMBDA=.726-308 ENERGY = -66.451406
JB> 2929 1.695E-04 4.941E-05 -66.451406 0.000E+00 10.32
JB> LINE SEARCH : LAMBDA=.163-307 ENERGY = -66.451406
JB> 2930 1.695E-04 4.941E-05 -66.451406 1.421E-14 10.29
JB> LINE SEARCH : LAMBDA=.136-309 ENERGY = -66.451406
JB> 2931 1.695E-04 4.941E-05 -66.451406 -1.421E-14 10.16
JB> LINE SEARCH : LAMBDA=.341-310 ENERGY = -66.451406
JB> 2932 1.695E-04 4.941E-05 -66.451406 0.000E+00 9.97
JB> UNIV| THE LEADING MINOR OF ORDER 1 IS NOT POSITIVE DEFINITE,
JB> UNIV| AND THE FACTORIZATION COULD NOT BE COMPLETED.
JB> STOPGM! STACK OF MAIN CALLS:
JB> STOPGM! CALL CNSTFC
JB> STOPGM! CALL CNSTFC
JB> STOPGM! CALL PCGRAD
JB> STOPGM! CALL RGSVAN
JB> PROGRAM STOPS IN SUBROUTINE UINV| ILLEGAL RESULTS DPOTRF
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--
=======================================================================
Axel Kohlmeyer e-mail: axel.kohlmeyer at theochem.ruhr-uni-bochum.de
Lehrstuhl fuer Theoretische Chemie Phone: ++49 (0)234/32-26673
Ruhr-Universitaet Bochum - NC 03/53 Fax: ++49 (0)234/32-14045
D-44780 Bochum http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/
=======================================================================
If you make something idiot-proof, the universe creates a better idiot.
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