1. Computational Sciences and Engineering Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA
2. Center for Nanophase Materials Sciences Oak Ridge National Laboratory Oak Ridge TN 37831 USA
3. Institute of Physics National Academy of Sciences of Ukraine 46, pr. Nauky Kyiv 03028 Ukraine
4. Institute for Problems of Materials Science National Academy of Sciences of Ukraine Krjijanovskogo 3 Kyiv 03142 Ukraine
5. Department of Materials Science and Engineering University of Maryland College Park MD 20742 USA