1. California NanoSystems Institute; University of California; Santa Barbara CA 93106 USA
2. Tohoku University WPI-AIMR and CNSI Joint Center; University of California; Santa Barbara CA 93106 USA
3. Beijing Computational Science Research Center; Beijing 10084 P.R. China
4. Materials Research Laboratory; University of California; Santa Barbara CA 93106 USA
5. Institut Néel, CNRS/Univ. Grenoble Alpes; BP 166 38042 Grenoble Cedex France
6. Department of Materials; University of California; Santa Barbara CA 93106 USA
7. Department of Chemistry and Biochemistry; University of California; Santa Barbara CA 93106 USA
8. Department of Chemistry and Biochemistry; University of California; Los Angeles CA 90095 USA