Direct Second Order MCSCF optimization methods for large CI expansions.

Development of linear and non-linear response theory for SCF and MCSCF wavefunctions.  Calculation of hyperpolarizabilities, two-photon transition moments and phosphorescence lifetimes using these methods.

Development of determinant based methods for full and restricted configuration interaction expansions.  Extensions to  relativistic Hamiltonians. Improved methods for solving eigenvalue problems for very large dimensions. Full CI benchmark calculations of ground state energies, excitation energies, equilibrium geometries of ground and excited states, electric properties and reaction energies.

Finite element methods for atomic MCHF calculations and their use to obtain accurate nuclear quadrupole moments by combining experimental quadrupole couplings and computed electric field gradients.

Development of coupled cluster methods allowing expansions with arbitrary excitation levels, and the use of these methods to estimate the contributions from quadruple and higher excitations to molecular constants and properties.

Proved, first  numerically and subsequently mathematically, that Moller-Plesset perturbation theory in general is divergent for electron-rich atoms and molecules.

Methods for the direct optimization of the atomic density matrix. Methods for correlated calculations of quantum dots.

Systematic calculations of of molecular equilibrium geometries, reaction enthalpies and atomization energies for small molecules to establish the accuracy of standard coupled cluster methods.