Molcas Forum

shuoshuo

Member

From: Beijing Normal University

Registered: 2017-10-18

Posts: 35

Is it possible to perform QMMM dynamic in current openmolcas ?

Dear molcas experts,

   I noticed that molcas has included the surface hopping dynamic module. I wonder is it possible to perform QMMM dynamic?  I have done QMMM (with tinker) geometry optimization before, during every QM step, a large number of MM part micro steps were done to minimize the energy. If I want to perform a QMMM dynamic, how would I avoiding MM part minimize the energy and maintain its temperature.

Here, I tried to write an input file, but not tested yet.

&GATEWAY
tinker
BASIS= 6-31G
GROUP= nosym

>>> FOREACH ITER IN (1 .. 2000)

  &SEWARD
  
  &ESPF
  	external
  	tinker mulliken

  >>> IF ($ITER == 1)

    &RASSCF
    LUMORB
    FileOrb= $Project.GssOrb
    Symmetry= 1
    Spin= 1
    nActEl= 6 0 0
    Inactive= 12
    RAS2= 5
    CIroot= 2 2 1

    >>> COPY $Project.JobIph $Project.JobOld

  >>> END IF
  &RASSCF
  JOBIPH
   CIRESTART
  Symmetry= 1
  Spin= 1
  nActEl= 6 0 0
  Inactive= 12
  RAS2= 5
  CIroot= 2 2 1
  MDRLXR= 2

  >>> COPY $Project.JobIph $Project.JobOld

  &SURFACEHOP
  TULLY
  SUBSTEP = 200
  DECOHERENCE = 0.1
  PSUB

  &ALASKA

  &DYNAMIX
  VELVer
  DT= 10.0
  VELO= 1
  THER= 1
  TEMP=300
  HOP=1

>>> END FOREACH

Best regard,
shuo

Last edited by shuoshuo (2018-06-11 08:24:10)

niko

Member

From: Marseille

Registered: 2015-11-08

Posts: 59

Website

Re: Is it possible to perform QMMM dynamic in current openmolcas ?

Hi, I don't have experience with the dynamics module, hence I can't comment on your input file.
About the MM minimization, you can simply avoid it by freezing most (or all) the MM atoms. This is achieved by using the Tinker's keyword ACTIVE in the key file.
Hope this helps.