A discussion of some aspects of the MCSCF method

After a brief overview of the MCSCF (Multi-Configuration Self- Consistent-Field) method, a more detailed examination of the underlying model is undertaken. The problem of ''multiple solutions'' is examined with reference to the ''symmetry-breaking'' problem and with emphasis on single-state cases. It is argued that the most appropriate resolution of such problems is usually case-specific, and depends on the details of how the MCSCF wave function is being used to model the chemical system rather than on features characteristic of the MCSCF wave function itself. Finally, a recently introduced MCSCF wave function optimization method based on multidimensional trigonometric interpolation is briefly discussed