Molcas Forum

lwang

Member

Registered: 2024-10-14

Posts: 13

How to follow the root in the PCM CASSCF optimization calculation

Dear all:
I want to optimize the structure of the first excited state i.e. RFROOT=2 with casscf under pcm solvent, but the root is flipped during the calculation, what keyword should I use to keep tracking the second root?
Below is my input file, I read a.11.RasOrb.2 as the pcm non-equilibrium anionic single-point casscf second root orbital。

 &GATEWAY
 coord = a.xyz
basis =Aug-cc-pvdz
 group = C1
 RF-input
 PCM-model; solvent= water
 End of RF-input
 RICD
>>> EXPORT MOLCAS_MAXITER = 500
>>> DO WHILE
&SEWARD
    DoAnalytical
 >>> If (iter = 1)
&RASSCF
   FILEORB =a.11.RasOrb.2
   Charge = -1
   spin=2
   nActEl=13 0 0
   Ras2=12
   ciroot =2 2 1
   Rlxroot=2
   RFROot=2
 >>> EndIf
&RASSCF
   Charge = -1
   spin=2
   nActEl=13 0 0
   Ras2=12
   ciroot =2 2 1
   Rlxroot=2
   RFROot=2
 &MCLR
   ITERations=500
   THREshold =1.0e-3
 &SLAPAF
 >>> END DO

Below is my casscf output section showing that the root has been flipped：

reading initial CI vectors from JOBIPH 
                        RF Root has flipped from 2  to 1 
                        Convergence after 29 iterations::    
                        RASSCF root number  1 Total energy:   -464.70252247::    
                        RASSCF root number  2 Total energy:   -464.69725559

Last edited by lwang (2025-04-19 07:48:14)

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,124

Re: How to follow the root in the PCM CASSCF optimization calculation

I don't think there's any automatic way. You'd have to manually change it and restart/resume the optimization.