HIGH-PRECISION ATOMIC COMPUTATIONS FROM FINITE-ELEMENT TECHNIQUES - 2ND-ORDER CORRELATION ENERGIES FOR BE, CA, SR, CD, BA, YB, AND HG

We have applied the FEM-MP2 method (an implementation of the p-version finite element technique within the framework of second-order Moller- Plesset perturbation theory, [J. Chem. Phys., 98, 5642 (1993), and ref erences therein]) to calculate second-order correlation energies for t he atoms Be, Ca, Sr, Ba, Yb, Cd, and Hg and thus to complete our studi es on closed-shell elements. The FEM-MP2 method permits the use of vir tual orbitals of very high angular momentum (l(max) = 12) in combinati on with radial basis sets which are very close to completeness, in suc h a way that we are able to obtain results that could be the most accu rate published so far and, in some cases, the only values available in the literature. We hope they may be useful as a reference for basis s et saturation tests and for new methods to calculate correlation energ ies. (c) 1994 by John Wiley and Sons, Inc.