1. Joint Institute for Advanced Materials, Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States
2. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
3. Institute of Physics, National Academy of Science of Ukraine, pr. Nauky 46, Kyiv 03028, Ukraine
4. Institute of Problems of Materials Science, National Academy of Science of Ukraine, Krjijanovskogo 3, Kyiv 03142, Ukraine
5. Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States