MCSCF

Hello,

I am just wondering if MRCC can run MRCI jobs based on MCSCF reference orbitals (without the use of an interface). If not, would it be possible to use MCSCF orbitals generated from ORCA as opposed to COLUMBUS or MOLPRO?

Thanks a bunch,
Colton

Dear Colton,
Yes, it is possible to use MCSCF orbitals with MRCC. See the description of keywords scftype, occ, docc, mact.
As an example, please consider the following input for an MRCISD calculation for water with a 2x2 CAS.

basis=cc-pVDZ
calc=CISD
scftype=mcscf
occ=3,1,1,0/3,1,1,0
docc=3,1,0,0
mact=1,0,1,0
mem=500MB

geom
H
O 1 R1
H 2 R1 1 A

R1=1.00000000000
A=104.0000000000

Hello,

Thanks for the quick response. Whenever I try to run my calculation, the Newton-Method always fails to converge. I am just wondering why this may be? If you need more info, let me know (I wasn't sure what would be needed).

Thanks a bunch,
Colton

Dear Colton,

Please, try to provide sufficient information so that we have a chance to reproduce your issue.
Full output files of the failed runs, version of the code (release date) would be a good start.
Do you use the binary or did you compiled the code yourself? If the latter, please share the compiler version.

Best wishes,
Peter