CASSCF/CASPT

The other half of the isomerization takes place directly bypassing a trappable intermediate, as recently confirmed by extensive theoretical calculations [B3LYP, CASPT 2, (8/8)CASSCF] [145],... 

CASSCF CASPT2(v) CASPT(c-v) INDO/S CASSI INDO/S... 

To set up a size-extensive perturbation theory, the zero-order Hamiltonian must be additively separable. We shall here show that, for multiplicatively separable zero-order wave functions, the CASSCF Fock operator and the zero-order energy are both additively separable but that the presence of projection operators nevertheless makes the zero-order CASPT Hamiltonian H ... 

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