1. Department of Chemistry, National University of Singapore, 3 Science Drive 3, 117543 Singapore
2. Institute for Materials Chemistry and Engineering (IMCE), Kyushu University, 744 Motooka, Nishiku, Fukuoka 819-0395, Japan
3. Solar Energy Research Institute of Singapore, National University of Singapore, 7 Engineering Drive 1, 117574 Singapore
4. Institute of High Performance Computing, 1 Fusionopolis Way, 138632 Singapore