Multi reference configuration interaction

The Cl methods described so far consider only CSFs generated by exciting electrons from a single determinant. This corresponds to having an HF type wave function as the reference. However, an MCSCF wave function may also be chosen as the 

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Bundgen P, Grein F and Thakkar A J 1995 Dipole and quadrupole moments of small molecules. An ab initio study using perturbatively corrected, multi-reference, configuration interaction wavefunctions J. Mol. Struct. (Theochem) 334 7... 

Werner H-J 1987 Matrix-formulated direct multiconfigurational self-consistent field and multi reference configuration interaction methods Adv. Chem. Phys. 69 1... 

Eq. (15b) for OH + H2 using multi reference configuration interaction wave functions. 

Grimme, S., Waletzke, M., 1999, A Combination of Kohn-Sham Density Functional Theory and Multi-Reference Configuration Interaction Methods , J. Chem. Phys., Ill, 5645. 

Structures were optimized at the theoretical level described in Table 1, footnote a. Final energies were obtained by using multi-reference configuration interaction (MRCI) wave functions including single and double excitations from die reference wave functions. cFrom Reference 8. 

Grimme S, Waletzke M (1999) A combination of Kohn-Sham density-functional theory and multi-reference configuration interaction methods, J Chem Phys, 111 5645-5655... 

Werner and co-workers [2, 21, 34] used internally-contracted multi-reference configuration-interaction (IC-MRCI) calculations, based on state-averaged (three-state) multi-configuration, self-consistent-field (MCSCF) calculations with large atomic orbital basis sets, to determine the three electronically adiabatic C1(F)+H2 PESs in the reactant arrangement L4, 2A, and lA. These all correlate with X( P) + H2. These three adiabatic electronic states are the IC-MRCI approximations to the three lowest eigenfunctions of Hgi, namely... 

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