1. Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
2. Google, Inc., Mountain View, California 94030, USA
3. Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
4. Chair for Theoretical Chemistry and Catalysis Research Center, Technische Universiät München, Lichtenbergstr. 4, D-85747 Garching, Germany
5. Argonne Leadership Computing Facility, Argonne National Lab, Lemont, Illinois 60439, USA
6. Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA