[1] IFF CSIC, Inst Fis Fundamental, C Serrano 123, Madrid 28006, Spain
[2] Pacific Union Coll, Dept Phys, Angwin, CA USA
[3] Southern Adventist Univ, Dept Phys & Engn, Collegedale, TN USA
[4] Univ Autonoma Madrid, Dept Quim Fis Aplicada, Unidad Asociada UAM CSIC, Madrid, Spain