Computational Chemistry and Molecular Modeling
Atomic, Molecular and Optical Physics
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
We apply the CFHH-GLF method, a modified version of our HH-GLF method, to directly solve the three-body Schrödinger equation for a set of He-like systems, including H-, He, Li+, Be2+, and B3+. Correlation functions with no adjustable parameters are determined from the cusp condition of the wave function. Our calculational results exhibit very fast and good convergence with hyperspherical harmonics (HH) and a generalized Laguerre function (GLF) and substantial improvement over the HH-GLF method. With only 36 HH and 6 GLF, we obtained the ground-state energy of -2.90371, -7.27988, -13.6555, and -22.0308 au for He, Li+, Be2+, and B3+, respectively. This compares with -2.89361, -7.26131, -13.6253, and -21.9859 au, respectively, by the HH-GLF method and Pekeris' results of -2.90372, -7.27991, -13.6556, and -22.0310 au, respectively. So, the inclusion of 36 HH and 6 GLF has yielded the precision of a few parts in 106 for He, Li+, Be2+, and B3+. However, our calculational results for H- are not so good. We analyzed the cause of this kind of exception and improved our calculations in this respect by using a slightly different correlation function. We finally obtained the ground-state energy of -0.527754 au for H- with 36 HH and 15 GLF, which is very near Pekeris' result of -0.527751 au and of the same order of precision as those achieved for other He-like ions. © 1995 John Wiley & Sons, Inc.
Type of Medium: