Xubo Wang

Keyword nvirt is no longer used in hci code. 64G of ram is not large, you can try with some larger epsilon which will require less resources or consider using...

Just shrink your (74e,179o) calculation to whatever space you actually want to correlate. If you want to have 20 doubly occupied orbitals and 50 empty orbitals, then do a calculation...

Yes, use a smaller active space would be proper for the purpose you described. restrict keyword is only experimental, correct me on this if I'm incorrect @sanshar , it is...