1. Department of Electrical and Computer Engineering; National University of Singapore; 4 Engineering Drive 3 117583 Singapore
2. Institute of Higher Performance Computing; 1 Fusionopolis Way 138632 Singapore
3. Department of Chemistry; NUS; 3 Science Drive 3 117543 Singapore
4. College of Materials Science and Engineering; Guangdong Research Center for Interfacial Engineering of Functional Materials; Shenzhen University; 3688 Nanhai Ave Shenzhen 518060 P. R. China