All-electron embedded correlated wavefunction theory for condensed matter electronic structure

We present an extension of our embedded configuration interaction method [P. Huang, E. A. Carter, J. Chem. Phys. 125 (2006) 084102], which models localized phenomena in metallic crystals as a finite cluster, embedded in an effective potential derived from orbital-free density functional theory. Here we extend the previous pseudopotential implementation to a frozen core, all-electron description of the background. Benchmark studies of the all-electron formulation are presented and compared with pseudopotential-based embedding for a Cu-2 dimer in Cu(1 1 1) and a Co adatom on Cu(1 1 1). Although we find subtle differences between the two methods, the same conclusions are reached, thereby validating the new all-electron formulation. (C) 2009 Elsevier B. V. All rights reserved.