Improved nonrelativistic energies for 1<i>s</i>²2<i>p</i>systems using a restricted variation method

Abstract

By using a restricted variation method, the nonrelativistic energies of the lithiumlike 1s22p systems are calculated. For lithium, the predicted nonrelativistic energy is –7.410 157 8(9)a.u. [Pipin and Bishop, Phys. Rev. A45, 2736 (1992)]. The results for systems with Z = 4-10 also give significant improvement over the recent results of Wang et al., Physica Scripta 47, 65 (1993). These results show that this restricted variation method could be very useful for high precision variation calculations.