1. Materials Department, University of California, Santa Barbara, California 93106-5050, USA
2. Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA
3. Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA
4. TCM Group, Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom
5. Department of Physics, University of California, Santa Barbara, California 93106-9530, USA
6. Center for Computational Materials Science, US Naval Research Laboratory, Washington, DC 20375, USA
7. Center for Physical Sciences and Technology (FTMC), Vilnius LT-10257, Lithuania