Atomic Structure: Variational Wave Functions and Properties

This chapter describes variational methods for the determination of wave functions either in nonrelativistic (LS), quasi relativistic Breit–Pauli (LSJ), or Dirac (jj) theory. The emphasis is on Hartree–Fock and multiconfiguration Hartree–Fock theory with reference to similar Dirac theory. Although the underlying mathematics of the latter is technically different because of the properties of Dirac spinors, we draw parallels between the nonrelativistic and relativistic formulations that lay the foundation of, respectively, the Atomic Structure Package (ATSP) 1 ; 2 and the General Relativistic Atomic Structure Package (GRASP) 3 ; 4 . Some results from the application of these multiconfiguration methods are presented for a number of atomic properties. Although framed entirely in terms of nonrelativistic calculations, the present chapter reveals a pattern that can be, and actually is, explored in the review article of variational theory 5 as in the following Chap. 23 on Relativistic Atomic Structure.