[CPMD-list] unknown error message

[Axel Kohlmeyer]

>>> "JZ" == Jin Zhao <zhaojin4576 at gmail.com> writes:

JZ> Dear All,

dear jin zhao,

JZ>       I'm trying to do a calculation of TiO2 using CPMD3.7. And it

please try to update to CPMD v3.9.1 (or at least v3.7.2).

JZ> doesn't converge for more than 600 circles. So I added the keyword:
JZ> PCG MINIMIZE, this time I got an error message like:

please note, that direct minimization for k-points does work as well
with CPMD as for gamma point calculations. lanczos diagonalization is
a slower, but more reliable alternative.

JZ>  ****************************************************************

JZ>  CPU TIME FOR WAVEFUNCTION INITIALIZATION:          41.82 SECONDS
JZ>  ***    RWFOPT| THE NEW SIZE OF THE PROGRAM IS  123744 kBYTES ***
JZ>  EWALD SUM IN REAL SPACE OVER  1* 1* 1 CELLS

since you are using k-points, you probably have a small cell,
so please have a look at the TESR parameter. for a small cell
it should be raised, (or RAGGIO lowered,) or else the ewald sum
will not be fully converged.

JZ>  STOPGM! STACK OF MAIN CALLS:
JZ>  STOPGM! CALL     K_FORC
JZ>  STOPGM! CALL     K_PCGR


JZ>  PROGRAM STOPS IN SUBROUTINE k_pcgrad| Line Search not implemented yet
JZ> ************************************************************************

JZ> I'm a rather beginner of CPMD. I really appreciate for any suggestions.

well, the program already gave you one: PCG MINIMIZE is not
implemented for k-points. so you have to use some other scheme 
to optimize your wavefunction, e.g. PGC (without MINIMIZE), 
ODIIS, or - as suggested above - lanczos.

best regards,
     axel kohlmeyer.

JZ> Best
JZ> Jin Zhao
JZ> _______________________________________________
JZ> CPMD-list mailing list
JZ> CPMD-list at cpmd.org
JZ> http://cpmd.org/mailman/listinfo/cpmd-list



--

=======================================================================
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.