MRCI calculation

[behnam nikoobakht]

Dear Molpro users,

I am trying to compute the excitation energy of IO2 using MRCI methods for several lower states. The energies that I got for these states are below 2 eV, which are not right . I attached the output file. I would appreciate it if you can kindly give a hint.

Thank you,

Behnam

[Peterson, Kirk]

Dear Behnam,

 

some comments on your input:

 

a) you chose a DK contracted basis set for Iodine but not for O.  You should also use aug-cc-pVTZ-DK for O.

 

b) just choosing a relativistically contracted basis set does not automatically turn on a relativistic Hamiltonian. Before you call the hf program you should include   "dkho=2"

 

c) I would recommend using "closed" rather than "frozen" in your multi step

 

regards,

 

-Kirk

 

From: molpr...@googlegroups.com <molpr...@googlegroups.com> on behalf of behnam nikoobakht <bniko...@gmail.com>
Date: Tuesday, May 14, 2024 at 12:08 PM
To: molpr...@googlegroups.com <molpr...@googlegroups.com>
Subject: [molpro-user] MRCI calculation

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[behnam nikoobakht]

Hello Kirk,

Thank you for your email and comments. I tried them and still it gives excited state energies below 2 eV.

The new output is attached.

Behnam

[Peterson, Kirk]

Hi Behnam,

 

it could simply be your geometry. Your bond lengths look quite long and the angle a bit short.  You might want to refer to the attached paper (assuming you don't already have it).

 

regards,

 

-Kirk