[CPMD-list] MD problem!

[Juerg Hutter]

Hi

> Dear all,
>
> I met the following problem when performing MD calculation!
>
>   367  0.00112    16.6    -294.14844    -294.14379    -294.14267   0.009   26.34
>   368  0.00114    16.9    -294.14855    -294.14380    -294.14267   0.009   25.94
>   369  0.00115    17.3    -294.14866    -294.14382    -294.14267   0.009   24.05
>   370  0.00116    17.6    -294.14877    -294.14383    -294.14267   0.008   25.49
>   371  0.00118    18.0    -294.14889    -294.14384    -294.14267   0.008   26.80
>   372  0.00119    18.4    -294.14901    -294.14386    -294.14267   0.008   27.22
>   373  0.00121    18.8    -294.14913    -294.14387    -294.14267   0.008   25.35
>   374  0.00123    19.2    -294.14926    -294.14389    -294.14266   0.008   25.89
>   375  0.00124    19.5    -294.14938    -294.14390    -294.14266   0.008   27.72
>   376  0.00126    19.9    -294.14951    -294.14392    -294.14265   0.008   25.37
>   377  0.00130    20.3    -294.14964    -294.14394    -294.14264   0.008   25.12
>   378  0.00135    20.7    -294.14973    -294.14391    -294.14257   0.008   24.31
>   379  0.04902    21.0    -294.14982    -294.14392    -294.09491   0.008   26.99
>   380*****************    -294.06582 3216785.58973**************   0.008   25.40
>
>  PROGRAM STOPS IN SUBROUTINE DSPEVY| FAILED TO DIAGONALIZE [PROC=   5]
>
> In the 379th steps, the electronic temperature becomes very high and the EHAM is not constant. So the timestep may be too long! But I perfom almost the same calculation with the same timestep and EMASS at the same system, the program runs okay! Moreover, the electron can follow the movement of Ion.
>

You are using a bad combination of EMASS and TIMESTEP for your system.
Obviously there is a difference between this and your other system
where the settings of the parameters work. Most likely this
system has a smaller electronic gap.
Reduce EMASS and probably TIMESTEP and see if you can get stable dynamics.

Juerg