Frozen orbitals

Dear Mihaly,

I would like to run a single reference eom-ccsd calculation with 10 occupied orbitals and only 100 virtual orbitals, and further want to freeze higher lying virtual orbitals.

Is such kind of calculation possible with mrcc ?

I was unable to find the according keywords in order to be able to freeze specific number of occupied and unoccupied orbitals for a single reference eom-ccsd calculation.

For instance in PSI4 we have the following keywords :

set FROZEN_DOCC [131]
set frozen_uocc [408]

Bests
Vafa

Dear Vafa,
You can freeze any number of occupied orbitals with the core keyword. The freezing of virtual orbitals is more complicated. You should formally run a MR calculation with setting the higher lying virtuals to inactive and excluding excitations to inactive orbitals. That is, for (EOM-)CCSD:
nacto=10
nactv=100
maxex=2
maxact=on
0 0

Just to report my result in case anyone is still searching for an answer.

I had the same question as Vafa, i.e. freezing both occupied and virtual in a single-reference (EOM-)CCSD calculation. Mihaly's solution solved it! Just don't forget `nacto` and `nactv` are specified as the number of spin orbitals (I got the number wrong in my first trial).