[CPMD-list] Problems on convergence!!

[Atte Sillanpää]

On 27 Mar 2003 duaj at fudan.edu wrote:

> Dear all,
>
> When I perform a geomertry optimization on methane(CH4) molecule using
> Vanderbilt ultrasoft pseudopotential and PCG MINIMIZE. When optimizing
> wavefunction, the maximum gradient of wavefunction grows bigger at first
> serveral steps, but keep constant later. The problems are as following:


> &DFT
>   NEWCODE
>   FUNCTIONAL PBE
>   GC_CUTOFF
>   0.2E-07
> &END
>

Try increasing the cut-off:

 GC-CUTOFF
  5.E-5

Start with random wavefunctions (in &CPMD section):

 INITIALIZE WAVEFUNCTION RANDOM

Hope this helps,

Atte

	atte.sillanpaa at oulu.fi		+358 (0)8 553 1681 (work), KE 368
	Dept. of Physical Chemistry	+358 (0)40 592 7369 (gsm)
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