Re: Alter Active space orbitals not working?

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Posted by Geetha on July 04, 2013 at 05:25:36:

In Reply to: Alter Active space orbitals not working? posted by Hung on March 19, 2013 at 01:19:06:

: Hi,

: I'm trying to calculate a simple CASPT2 calculation for s-trans butadiene, but when the output comes out, I see that one of the orbitals included in the active space should be exchanged out for one of the inactive ones. I tried the alter kw, and I am getting the correct output for exchange:

: "Molecular orbitals exchanged:
: In symmetry 1 : 18 17"

: However, when I view the buta.rasscf.molden file, I see that the orbitals have not been exchanged, and I get the same final energy as when I had not exchanged them. Is there something I'm doing wrong? I'm sure that the two orbitals need to be exchanged, but I can't seem to get it to work. Can I get some help? Is there another way to exchange the orbitals? If needed, I can include my input file.

Though the MOs are exchanged in the initial guess (lumorb/jobold), after going thro further optimizations (both MO and CI coefficients) the MOs can still move out of the CAS space due to insufficient/proper CAS space for a particular symmetry. I was looking at the forum for an answer to this question. I am trying to increase the CAS space and studying the character of MO orbitals. If you have already got some answers, please mail to my id (

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if B is 1s22s22p1, what is Li?



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