Accurate and simple wavefunctions for the helium isoelectronic sequence with correct cusp conditions

K.V. RODRIGUEZ, G. GASANEO, D.M. MITNIK

JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS

IOP

Lugar: Bristol, London; Año: 2006

0953-4075

Simple and accurate wavefunctions for the He atom and He-like isoelectronic ions are presented. These functions -- the product of hydrogenic one-electron solutions and a fully-correlated part -- satisfy all the coalescence cusp conditions at the Coulomb singularities. Functions with different number of parameters and different degrees of accuracy are discussed. Simple analytic expressions for the wavefunction and the energy, valid for a wide range of nuclear charges, are presented.