Session S5 - Atoms and Ions.
ORAL session, Saturday morning, October 25
LaPaz, Memorial Union
We treat the spin-orbit interaction in many-electron systems within variational and diffusion Monte Carlo. We explicitly include the spin degrees of freedom by putting a two-component spinor on each electron. In our all-electron atomic calculations, the spin-orbit interaction is a parameter-free relativistic correction to the Schrodinger equation. This interaction is simply the local electric field at each electron, which appears as a magnetic field in that electron's rest frame. Thus our many-body calculations give the atomic spin-orbit coupling strengths by evaluating the electric field from the nucleus and all other electrons, and coupling to the electron's spin and velocity. We illustrate this method on first and second row atoms, and discuss its potential applications to solids and molecules. (Work supported by DARPA/ONR )