1. Institute of Molecular Sciences, Shanxi University, Taiyuan 030006, People's Republic of China, Xinzhou Teachers' University, Xinzhou 034000, Shanxi, People's Republic of China, Department of Physics, Washington State University, 2710 University Drive, Richland, Washington 99354, and Chemical and Materials Sciences Division, Pacific Northwest National Laboratory, MS K8-88, P.O. Box 999, Richland, Washington 99352