Model potential in spectral representation form. Its fidelity to the frozen-core operator and comparison with other model potentials

The model potential, in which the Coulomb and exchange core operators are converted to the matrix elements by use of the spectral representation technique, should be equivalent to the frozen-core operator, if the basis set of the spectral representation is complete. Its fidelity to the frozen-core operator is examined in this paper through a thorough study of basis set convergence in both the spectral space and the atomic orbital space, along with comparison with the Sakai–Huzinaga and the Huzinaga–Seijo–Barandiaran–Klobukowski model potentials. The RHF molecular calculations on N2, P2, As2, Sb2, PN, and AsN show that the present model potential can approximate, with reliable accuracy, the results obtained from the frozen-core calculations. Keywords: model potential, spectral representation, molecular orbital calculation, electronic structure.