Pauli principle corrections in particle-hole state densities

A recent method for calculating particle-hole state densities is shown to be exact only when the number of excited particles equals the number of excited holes. Modifications are proposed for the cases where p≠h. For the p=h case, comparisons of the exact results with the Williams analytical formula had pointed to inadequacies in the latter, but were made without considering the need for an energy dependent Pauli correction term. More careful investigation supports the continued use of the Williams formula with the appropriate Pauli correction term. (orig.)