Progress with BERTHA a Relativistic Atomic and Molecular Structure Package

QUINEY School of Physics, University of Melbourne, Victoria 3010, Australia  

Abstract. BERTHA is a 4-component relativistic molecular structure program based on relativistic Gaussian (G-spinor) basis sets which is intended to make affordable studies of atomic and molecular electronic structure, particularly of systems containing high-Z elements. This paper reviews some of the novel technical features embodied in the code, and assesses its current status, its potential and its prospects. 

Recent Advances in the Theory of Chemical and Physical Systems, 199-215. 2006 Springer. Printed in the Netherlands. 

This paper outlines the current status of the BERTHA program. This has been named (with her approval) after Lady Jefferies (f902-f999) nee Bertha Swirles), a colleague of D.R. Hartree at Cambridge University and a distinguished applied mathematician who, amongst other achievements, wrote the earliest paper on relativistic self-consistent fields for atoms [f]. 

A full account of the theory of relativistic molecular structure based on standard QED in the Furry picture will be found in a number of publications such as [7, Chapter 22], [8, Chapter 3]. These accounts use a relativistic second quantized formalism. For present purposes, it is sufficient to present the structure of BERTHA in terms of the unquantized effective Dirac-Coulomb-Breit (DCB) A-electron Hamiltonian  

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PROGRESS WITH BERTHA A RELATIVISTIC ATOMIC AND MOLECULAR STRUCTURE PACKAGE... 

I. P. Grant and H. M. Quiney, Progress with BERTHA A relativistic atomic and molecular structure package, this Volume. 

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