QWalk: A quantum Monte Carlo program for electronic structure

We describe QWalk, a new computational package capable of performing quantum Monte Carlo electronic structure calculations for molecules and solids with many electrons. We describe the structure of the program and its implementation of quantum Monte Carlo methods. It is open-source, licensed under the GPL, and available at the web site http://www.qwalk.org. (C) 2009 Elsevier Inc. All rights reserved.