Molcas Forum

angeloraymondrossi

Member

Registered: 2024-04-04

Posts: 17

Obtaining Initial Geometries for Other Further Calculations

Hello,

I am trying to obtain an initial set of coordinates of a molecule which will be used for other separate calculations.

To accomplish this I have wrapped an AIMD calculation in a loop ..

>> EXPORT MOLCAS_MAXITER=1000
>> DOWHILE

&RASSCF
 JOBIPH; CIRESTART  /* CIRESTART is needed becaus pre-optimized vector stored in JOBIPH is to be used */
 Symmetry= 1
 Spin= 1
 nActEl= 4 0 0
 Inactive= 11   /* Number of inactive orbitals */
 RAS2= 4        /* Number of active 0rbitals   */
 CIroot= 4 4 1  /* Total 3 states, ground + 2 excited, equal weight */
 MDRLXR= 2      /* Second root is chosen for gradient calculation   */

>> COPY $Project.JobIph $Project.JobOld

&ALASKA

&DYNAMIX
 VELVer
 DT= 41.3
 VELO= 3
 THER= 2
 HOP= 1
 TEMP=300.0

>> EVAL N = NITER

 >> COPY  $PWD/$PROJECT.md.xyz $PWD/$PROJECT.md.$N.xyz 

>> ENDDO

This is not working.  On obvious reason for the problem is that $PROJECT.md.xyz is a cumulative/additive file that provides the complete trajectory.   What I need is the coordinates (i.e. the current frame) from the current iteration (NITER), and I don't know how to obtain them.  Of the 1000 xyz frames of the complete trajectory, I will choose 100 frames to provide a reasonable sampling of the various conformations of the molecule.

Can you provide ideas on how to copy the current set of coordinates from the &DYNAMIX loop?  I really appreciate any help you can provide.

Kind regards,
Angelo

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,085

Re: Obtaining Initial Geometries for Other Further Calculations

You're missing SEWARD inside the loop. Without it, you're stuck with the first integrals computed, and your RASSCF is just redoing the same calculation again and again.

DYNAMIX should be updating the coordinates in the RunFile, which is read by SEWARD, so you don't need to manually save and copy the coordinates. You can find an example in the manual: https://molcas.gitlab.io/OpenMolcas/sph … namix.html