Molcas Forum

Anugraha

Member

Registered: 2025-12-17

Posts: 22

Convergence issue with excited state optimization using CASSCF

Dear Molcas Development Team,

I am performing an excited state geometry optmization using CASSCF module on my molecule which is composed of pyrrole and water. I have added a floating point/ dummy atom  between them  and provided s and p diffuse functions on the floating point. Below is my input :

But the caculation is not converging . I am attaching my .log file and error

I would be thankful if anyone could suggest how to resolve this issue.

Thank you
Anugraha C P

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,204

Re: Convergence issue with excited state optimization using CASSCF

To increase the number of iterations, set the environment variable MOLCAS_MAXITER to a higher number (default is 50).

Or just consider your geometry converged, as the gradient is already below the threshold.

Anugraha

Member

Registered: 2025-12-17

Posts: 22

Re: Convergence issue with excited state optimization using CASSCF

To increase the number of iterations, set the environment variable MOLCAS_MAXITER to a higher number (default is 50).

Or just consider your geometry converged, as the gradient is already below the threshold.

Sir, I have modified the input by increasing the maximum iterations as well as changing the threshold values in SLAPAF.

& SLAPAF
Thrshld = 1.0d-6 3.0d-4 , and the optimization was converged.

But the calculation was aborted with a status of  "MCLR: Solving CP(CAS)HF equations for perturbation  45."

Iam attaching the warning in the MCLR module and the end of the .log file

Let me please know how can i solve this problem.

Thank you