DETERMINATION OF HIGHER ELECTRIC POLARIZABILITY TENSORS FROM UNRELAXED COUPLED-CLUSTER DENSITY-MATRIX CALCULATIONS OF ELECTRIC MULTIPOLE MOMENTS

The CCSDT-1 method is used to calculate electric dipole, quadrupole, a nd octopole moments for the HF and H2O molecule and the F- anion, toge ther with the associated higher-order polarizabilities. All multipole moments are computed as expectation values. Externally perturbed momen ts are used to determine the components of the electric tensors of sec ond and higher order. It is shown that the correlated electric moments are in good agreement with experiment and that they may be used to ob tain the electric polarizability and hyperpolarizability tensors in an effective way. (C) 1994 John Wiley & Sons, Inc.