[CP2K:2591] Constraint

Teodoro Laino teodor... at gmail.com
Thu Feb 25 16:05:42 UTC 2010


Dear Rupa,

I assume you have the knowledge to read web pages. Could you please read 
(carefully) these couple of  links?
http://cp2k.berlios.de/manual/CP2K_INPUT/MOTION/CONSTRAINT/COLLECTIVE.html#desc_TARGET

and also:
http://cp2k.berlios.de/manual/CP2K_INPUT/MOTION/CONSTRAINT/COLLECTIVE.html#desc_TARGET_GROWTH

After that, check again these two lines of your input:

      TARGET 5
      TARGET_GROWTH 0.0001


specifically regarding the units.
Regards,
Teo

rupa wrote:
> Hi all,
> I have some problem with constrained MD of water-dimer with O--O
> distance as constraint, which is required to extent up to 5 �.
> However, the required criteria was not satisfied in the simulation,
> the extension of O--O distance was beyond 5 �.
> Any suggestion in this regard is appreciated.
>
> Thanks
> Rupa
>
> P.S. Input file is provided below for reference.
>
> &FORCE_EVAL
>   METHOD Quickstep
>   &DFT
>     BASIS_SET_FILE_NAME GTH_BASIS_SETS
>     POTENTIAL_FILE_NAME POTENTIAL
>     &MGRID
>       CUTOFF 280
>       NGRIDS 1
>       REL_CUTOFF 50
>     &END MGRID
>     &QS
>       EPS_DEFAULT 1.0E-12
>       EPS_GVG 1.0E-6
>       EPS_PGF_ORB 1.0E-6
>     &END QS
>     &SCF
>       EPS_SCF 1.0E-6
>       MAX_SCF 350
>       SCF_GUESS atomic
>     &END SCF
>     &XC
>       &XC_FUNCTIONAL BLYP
>       &END XC_FUNCTIONAL
>       &VDW_POTENTIAL
>         POTENTIAL_TYPE PAIR_POTENTIAL
>         &PAIR_POTENTIAL
>          &END PAIR_POTENTIAL
>       &END VDW_POTENTIAL
>     &END XC
>     &POISSON
>       PERIODIC NONE
>       POISSON_SOLVER MT
>     &END POISSON
>   &END DFT
>   &SUBSYS
>     &CELL
>       ABC 20.000 20.000 20.000
>       PERIODIC NONE
>     &END CELL
>     &COORD
>      H 0.828857203  1.510765153  1.850758135
>      O 0.223273347  1.612802255  1.087529046
>      H 0.746091252  2.082274953  0.419190658
>      O 1.531077052  1.395421022  3.663417772
>      H 1.345748937  0.482975975  3.940795058
>      H 0.806283419  1.920091495  4.042933787
>     &END COORD
>     &KIND O
>       BASIS_SET TZVP-GTH
>       POTENTIAL GTH-BLYP-q6
>     &END KIND
>     &KIND H
>       BASIS_SET TZVP-GTH
>       POTENTIAL GTH-BLYP-q1
>     &END KIND
>     &COLVAR
>       &DISTANCE
>        ATOMS 2 4
>       &END DISTANCE
>     &END COLVAR
>   &END SUBSYS
> &END FORCE_EVAL
>
> &GLOBAL
>   PROJECT md
>   RUN_TYPE MD
>   PRINT_LEVEL LOW
> &END GLOBAL
>
> &MOTION
>   &MD
>     ENSEMBLE NVT
>     STEPS  4000
>     TIMESTEP 1.0
>     TEMPERATURE 300.0
>     &THERMOSTAT
>       &NOSE
>         LENGTH 3
>         YOSHIDA 3
>         TIMECON 100.
>         MTS 2
>       &END NOSE
>     &END THERMOSTAT
>   &END MD
>   &CONSTRAINT
>     SHAKE_TOLERANCE 1.0E-08
>     &COLLECTIVE
>       COLVAR 1
>       INTERMOLECULAR
>       TARGET 5
>       TARGET_GROWTH 0.0001
>     &END COLLECTIVE
>   &END CONSTRAINT
> &END MOTION
>
>   




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