Molcas Forum

MQC

Member

Registered: 2020-12-17

Posts: 5

How to obtain RasOrb with Improved Virtual Orbitals (IVO)

Dear all,

I am trying to obtain improved virtual orbitals from a previously converged RASSCF calculation. For doing that, I have employed the previous RasOrb as INPORB, set CIMX=0 and included the IVO keyword. In the output file, new virtual orbitals are written (therefore the keyword is working) but when I try to visualize them, they are just the same orbitals I used as input.  So I have checked RasOrb files and the coefficients of the virtual orbitals do not match the ones in the output file, they are just the virtual orbitals from the starting RasOrb. My question is if is there any missing keyword to print the IVO orbitals in  the RasOrb file.

Thanks in advance.

Last edited by MQC (2020-12-17 20:10:42)

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,085

Re: How to obtain RasOrb with Improved Virtual Orbitals (IVO)

If you want to keep previous orbitals, shouldn't you use the CIONLY keyword (instead of CIMX)?

MQC

Member

Registered: 2020-12-17

Posts: 5

Re: How to obtain RasOrb with Improved Virtual Orbitals (IVO)

Thanks for your response. I do not see why CIMX=0 wouldn't keep the orbitals. I have run the calculation both ways and the results are the same regardless of the keyword employed. In the output, occupied orbitals match the input orbitals and virtual orbitals changed due to the IVO keyword, so they keyword is working. The issue here is that these new improved virtual orbitals of the output have not been written either in the RasOrb or the molden files, they are just the same starting orbitals.

Ignacio

Administrator

From: Uppsala

Registered: 2015-11-03

Posts: 1,085

Re: How to obtain RasOrb with Improved Virtual Orbitals (IVO)

I personally haven't used the IVO keyword, and I'm not quite sure how it works. I know it was a relatively recent addition, and possibly not much tested, it may be that it doesn't work if orbitals are not optimized. You could try without the CIMX or CIONLY keywords, and instead freezing all inactive orbitals, or using the CIRESTART keyword (if the calculation was already converged, it should converge "fast" too, but you'd need the JobIph or rasscf.h5 file).

nikolay

Member

From: Stuttgart

Registered: 2016-03-21

Posts: 54

Re: How to obtain RasOrb with Improved Virtual Orbitals (IVO)

They could be in the $Project.RasOrb.1 file. For sure with CIONLY option, the $Project.RasOrb has to be the same as INPORB.