[CP2K:315] Minimization error with CG
Teodoro Laino
teodor... at gmail.com
Fri Oct 5 14:38:06 UTC 2007
Luca,
The error you get with CG means that gradients are too large..
Rescaling the forces may help.. have a look at:
http://cp2k.berlios.de/input/
InputReference~__ROOT__~FORCE_EVAL~RESCALE_FORCES.html
or just starting from a geometry that has been annihilated with MD..
Anyway the very large forces may be due to your input file.
There are quite several things wrong in it:
1) Important: CONSTRAINTS at the moment DO NOT work with the geometry
optimizer..
2)
>
>
> &FORCE_EVAL
> METHOD FIST
>
> &MM
> &FORCEFIELD
> PARM_FILE_NAME ./par_amber2charmm.inp
> PARMTYPE CHM
> EI_SCALE14 0.8333
> VDW_SCALE14 1.0
> &SPLINE
> UNIQUE_SPLINE T
> EMAX_SPLINE 0.5
> &END SPLINE
> &END FORCEFIELD
>
You're using just 1 spline.. so the spline generation cannot be slow
(as you said).. If you use the full set of spline than.. yes.. it
could be slow...
3) You're not using any kind of electrostatic (EWALD_TYPE NONE)!! is
this really what you want??????????
Periodic NONE is not supported for MM run.. all MM run can be
performed only in full periodicity (at the moment)...
> &POISSON
> &EWALD
> EWALD_TYPE NONE
> ALPHA 0.44
> GMAX 64
> O_SPLINE 6
> &END EWALD
> PERIODIC NONE
> &END POISSON
>
4) PERIODIC NONE has no sense since you cannot do calculations that
are not periodic with MM..
> &CELL
> ABC 57.000 60.0 53.000
> UNIT ANGSTROM
> PERIODIC NONE
> &END CELL
Anyway I will look into the segfault (this could be due to the fact
that SAVE_MEM was never tested for GEO_OPT)..
Teo
More information about the CP2K-user
mailing list