1. Department of Materials Science and EngineeringKorea Advanced Institute of Science and Technology (KAIST) 291 Daehak‐ro, Yuseong‐gu Daejeon 305‐701 Republic of Korea
2. Computational Science Research CenterKorea Institute of Science and Technology (KIST) Seoul 02792 Republic of Korea
3. Department of Electrical and Computer EngineeringUniversity of Toronto 10 King's College Road Toronto Ontario MSS 3G4 Canada
4. Center for Hydrogen and Fuel Cell ResearchKorea Institute of Science and Technology (KIST) Seoul 02792 Republic of Korea