[molpro-user] Extended Multi-State CASPT2

[Werner Győrffy]

Dear Alan,

CLOSED orbitals are doubly occupied in all reference configurations but 
excitations are allowed from them in the CASPT2 calculations if they are 
not frozen. If you want to define orbitals which are frozen (not 
correlated) in CASPT2, you should use CORE orbitals. CORE orbitals are 
not counted for the 32 orbital limitation in the rs2 program.

Active orbitals in CASSCF are defined as OCC minus CLOSED orbitals.

An (X)MS-CASPT2 calculation is still possible only with the rs2 program 
not with rs2c.

Regards,

Werner Gyorffy.



On 07/01/2014 11:56 PM, Alan Chien wrote:
> Interesting nugget of information. The example given in the multi-state
> CASPT2 section of the manual DOES change its active space when you
> change the numbers in the closed card.
> So it seems that for that particular example it can recognize closed input.
>
> Example: http://www.molpro.net/info/current/examples/lif_mr_mscaspt2.com
> (I edited it so that it only did r=3 ang to reduce the amt of output I
> had to look at. Also removed everything below RS2 section)
>
> Trying to replicate it now. In fact, been trying for a while.
>
>
>
>
> On Tue, Jul 1, 2014 at 3:48 PM, Alan Chien <alandc at umich.edu
> <mailto:alandc at umich.edu>> wrote:
>
>     Dear Molpro Community,
>
>     I was wondering if there was something wrong with my following input
>     for an extended multi-state CASPT2 calculation. My input is not
>     recognizing the CLOSED card, and so is throwing the error "TOO MANY
>     ACTIVE ORBITALS: 48 THIS VERSION ALLOWS 32." An old thread mentions
>     that I should use RS2C -
>     http://www.molpro.net/pipermail/molpro-user/2006-April/001759.html -
>     which should recognize closed orbitals.
>
>     But it's a rather old thread, and I want XMS-CASPT2 which isn't
>     implemented for RSC2, and so I thought it worth mentioning to see if
>     they had updated the RS2 code and perhaps my input was just off. The
>     manual makes no mention of RS2 being unable to recognize the CLOSED
>     card. I also tried the same input with FROZEN and that threw the
>     same error.
>
>     Any input welcome,
>     Alan Chien
>
>
>     ***,title
>     memory,400,m
>     symmetry
>     geometry={
>       S          1.9692714536        0.9837700026        0.0000000000
>       C          0.6745300892       -0.1941173367        0.0000000000
>       C          1.1941024748       -1.4906632561        0.0000000000
>       C          2.5920412491       -1.5265017306        0.0000000000
>       C          3.1677860531       -0.2809638443        0.0000000000
>       C         -0.6745300892        0.1941173367        0.0000000000
>       C         -1.1941024748        1.4906632561        0.0000000000
>       C         -2.5920412491        1.5265017306        0.0000000000
>       C         -3.1677860531        0.2809638443        0.0000000000
>       S         -1.9692714536       -0.9837700026        0.0000000000
>       C         -4.5811338904       -0.0064991780        0.0000000000
>       C         -5.5229897499        1.0602944736        0.0000000000
>       N         -6.2538051640 <tel:2538051640>        1.9321608642
>       0.0000000000
>       C          4.5811338904        0.0064991780        0.0000000000
>       C          5.5229897499       -1.0602944736        0.0000000000
>       N          6.2538051640 <tel:2538051640>       -1.9321608642
>       0.0000000000
>       C          5.0766433381        1.3388671764        0.0000000000
>       N          5.4513787354        2.4133206959 <tel:4133206959>
>       0.0000000000
>       C         -5.0766433381       -1.3388671764        0.0000000000
>       N         -5.4513787354       -2.4133206959 <tel:4133206959>
>       0.0000000000
>       H         -3.1636666579        2.4343293653 <tel:4343293653>
>       0.0000000000
>       H         -0.5803308458 <tel:5803308458>        2.3697711304
>       0.0000000000
>       H          0.5803308458 <tel:5803308458>       -2.3697711304
>       0.0000000000
>       H          3.1636666579       -2.4343293653 <tel:4343293653>
>       0.0000000000
>     }
>
>     basis=6-31G*
>     hf
>     {casscf;
>     closed,31,6,30,5 !core orbs, total 72
>     occ,31,8,30,7     !active orbs, total 76
>     wf,148,1,0;state,2
>     wf,148,3,0
>     pspace,100.0
>     }
>
>     {rs2,xms=1,mix=2;
>     state,2,2,3
>     }
>
>
>
>
>
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