QUADRUPOLE AND OCTUPOLE CAUCHY MOMENTS OF THE ATOMS THROUGH ARGON

Quadrupole and octupole Cauchy moments of the atoms through argon are calculated using the hydrodynamic formulation of time-dependent Kohn-S ham theory. The exchange-correlation energy density functional is appr oximated by a gradient expansion for atoms that has an explicit depend ence upon the number of electrons. The first-order corrections to the Kohn-Sham amplitudes and phases are found by seeking variational solut ions of the derived sequential set of functionals. The trial functions employed contain both linear and nonlinear variational parameters and are thus flexible enough to provide rapid convergence to the multipol e polarizabilities. The resulting Cauchy moments provide information t hat allows the calculation of various properties that result from the linear interaction of atoms with a time-varying electric field. (C) 19 94 John Wiley and Sons, Inc.