Calculation of the Stark effect of neon I usingjl coupled wave functions

A method to calculate the Stark shifts and splittings in noble gases is described and results for neon I are presented. The energy values in a static homogeneous electric field are found by diagonalizing the energy matrix numerically. This matrix consists of the energy values of the free atom taken from experiment and of off-diagonal matrix elements of the electric field operator. The latter are computed using wave functions consisting of a radial function of the excited electron found by numerical integration, and of a two-particle (core+electron) spin-orbital part represented by rigorousjl coupling. As an example, the splitting of the levels 6s to 6p is shown and is explained in terms of atomic level positions, the relative size of matrix elements and of selection rules. A nomenclature for the high field Stark effect is developed in accord with group theory.