1. Department of Physics and Astronomy University of California at Irvine Irvine CA 92697 USA
2. Department of Computer Science Tennessee Technological University Cookeville TN 38505 USA
3. Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 37831 USA
4. Chemical Sciences Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA
5. Computational Science and Mathematics Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA