A multi-configuration optimised central potential method for atomic structure calculations: application to carbon

A multi-configuration optimised central potential model for atomic structure is described. In this model, the expectation value for the Hamiltonian is minimised by varying the central potentials in which are calculated the orbitals of the multi-configuration atomic state. Each potential satisfies a linear integral equation which is solved numerically. Results for the energies of some low-lying even- and odd-parity states of carbon are given and compared with experiment as well as with multi-configuration Hartree-Fock and close-coupling calculations. As in the case of the single-configuration optimised potential model, whose generalisation is presented here, the results compare favourably with those from other rather more complicated methods.