1. Solid State Theory Group, Materials and Chemical Sciences, Pacific Northwest National Laboratory, Richland, Washington 99352, and Department of Chemistry, University of Utah, Salt Lake City, Utah 84112
2. JILA, University of Colorado, Boulder, Colorado 80309-0440, and Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
3. Department of Chemistry, University of Gdańsk, 80-952 Gdańsk, Poland