1. Department of Geosciences, Texas Tech University, Lubbock, USA
2. School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, People's Republic of China
3. Institute of Theoretical Chemistry, University of Vienna, Vienna, Austria
4. Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, USA
5. Institute for Soil Research, University of Natural Resources and Life Sciences, Vienna, Austria