1. Department of Physics and Astronomy, Mississippi State University, Mississippi State, MS 39762, U.S.A.
2. HPC Center for Computational Sciences, Mississippi State University, Mississippi State, MS 39762, U.S.A.
3. Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
4. Department of Physics, University of Arizona, Tucson, AZ 85721, U.S.A.