[1] Univ Florida, Dept Chem, Gainesville, FL 32611 USA
[2] CNRS, Lab Louis Neel, F-75700 Paris, France
[3] Indiana Univ, Dept Chem, Bloomington, IN 47405 USA
[4] Indiana Univ, Ctr Mol Struct, Bloomington, IN 47405 USA
[5] Univ Calif San Diego, La Jolla, CA 92093 USA