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 references therein]) to calculate second-order correlation energies for the atoms Be, Ca, Sr, Ba, Yb, Cd, and Hg and thus to complete our studies on closed-shell elements. The FEM-MP2 method permits the use of virtual orbitals of very high angular momentum (l(max) = 12) in combination with radial basis sets which are very close to completeness, in such a way that we are able to obtain results that could be the most accurate 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 set saturation tests and for new methods to calculate correlation energies. (c) 1994 by John Wiley and Sons, Inc.