Walter J. Stevens

TL;DR: Relativistic compact effective potentials (RCEP) as mentioned in this paper were derived from numerical Dirac-Fock atomic wavefunctions using shape-constrained shapes.

TL;DR: In this article, the angular-dependent components of these potentials are represented by compact one-and two-term Gaussian expansions obtained directly from the appropriate eigenvalue equation, and energy optimized Gaussian basis set expansions of the atomic pseudo-orbitals, which have a common set of exponents for the s and p orbitals, are also presented.

TL;DR: In this paper, a complete set of effective core potentials (ECPs) and valence basis sets for the lanthanides (Ce to Lu) are derived, and the results of atomic calculations indicate that the greatest error vs highly accurate numerical potential/large, eventempered basis set calculations results from replacement of the large, even-tempered base sets with more compact representations.

TL;DR: The effective fragment potential (EFP) method as discussed by the authors was developed to describe aqueous solvation, by representing Coulombic, induction and repulsive interactions via one-electron terms in the ab initio Hamiltonian.

TL;DR: In this article, an effective fragment model is developed to treat solvent effects on chemical properties and reactions, and formulae are presented that permit the determination of analytic energy gradients and numerically determined energy second derivatives (hessians) for the complete system.