Molcas Forum

rishu

Member

Registered: 2020-10-03

Posts: 23

Difference density analysis of the different states

Hi
I am doing the ground and excited state calculations of the molecule and I want to analyse the difference density to see the movement of electron from ground to excited state. Can anyone please explain how can I do that in Openmolcas?

Best
Rishu

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,011

Re: Difference density analysis of the different states

If you compute ground and excited states with a single state-average RASSCF call, or with RASSI, you can plot the difference density directly with Pegamoid (if you have HDF5 enabled). Otherwise, you can still compute the densities separately with Pegamoid, save them as cube files, and subtract the densities manually (it should be pretty trivial) or with an external tool like https://www.cp2k.org/tools:cubecruncher

rishu

Member

Registered: 2020-10-03

Posts: 23

Re: Difference density analysis of the different states

Thanks, Ignacio.
I have two separate calculations for the ground and the excited state.

May I ask you how can I plot the spin density with Pegamoid?

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,011

Re: Difference density analysis of the different states

The spin density should be available from the orbital dropdown if there is any spin information in the file (see e.g. https://gitlab.com/Jellby/Pegamoid/-/bl … ype=heads). If there isn't, maybe it's because you have a singlet? You can also open the SpnOrb files, if there's any.