The authors gratefully acknowledge the financial support of the National Basic Research Program of China (No. 2014CB643401), the National Natural Science Foundation of China (Nos: 21607176, 51134007 and 20773036), the Science and Technology Planning Project of Hunan Province, China (No. 2016SK2088), and the Research Foundation of Education Bureau of Hunan Province, China (No. 16B274); Partial ab initio XANES computation was performed on the High Performance Computing Center of Central South University; N.Z. particularly appreciates the China Scholarship Council (No. 201306370118), who fund him to visit the J. Brugger lab. This research used resources of the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Barbara Etschmann, Jay R. Black, Pascal V. Grundler, and Dale Brewe are thanked for their help in collecting the data.