Multi-configuration self-consistent field. More than one configuration ( Hartree-Fock-type determinant) is used to describe the wavefunction. Both the coefficients of the configurations and the orbital coefficients are optimized. This is a limited type of CI (configuration interaction), with the added feature of orbital optimization. See CASSCF.

(MultiConfiguration Self-Consistent Field) A limited type of CI. A simple extension of the SCF approach to include non-dynamic electron correlation, with the added feature of orbital optimization. A number of configurations are chosen in some manner, then both the expansion coefficients and the orbital coefficients are optimized.