ZORA and ECP

3:45:17 AM PDT - Thu, Sep 22nd 2011
Dear all, I have accidentally run a calculation where I used ECP and ZORA at the same time. Is this combination allowed from a physical point of view ? Or would it just lead to spurious results ?

Forum Vet

10:46:11 AM PDT - Thu, Sep 22nd 2011
It could lead to double counting of relativistic effects as the ECP effectively incorporates the expansion and contraction of valence orbitals. Bert Quote: Sep 22nd 10:45 am Dear all, I have accidentally run a calculation where I used ECP and ZORA at the same time. Is this combination allowed from a physical point of view ? Or would it just lead to spurious results ?[/quote]