1. School of Chemical Sciences NMR Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
2. School of Chemical Sciences George L. Clark X-Ray Facility and 3M Materials Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
3. Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States