High accuracy Dirac-finite-element (FEM) calculations for H2+ and Th2179+
Physics Department, University of Kassel, 34132 Kassel, Germany
Revised: 12 July 2001
Published online: 15 November 2001
A two-dimensional, fully numerical approach to the four-component first-order Dirac-differential-equation utilizing the Finite-Element-Method (FEM) is employed for H and Th. Using elliptic-hyperbolic coordinates and further one-dimensional singular transformations, scaling transformations and extrapolation techniques (geometrical over iteration steps and logarithmic over grid points) we achieve for the molecules H and Th relative accuracies better than 10-12 for 1(1/2)g energies.
PACS: 02.70.Dh – Finite-element and Galerkin methods / 03.65.Ge – Solutions of wave equations: bound states / 31.15.Ar – Ab initio calculations
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001