Effective bond charges from infrared intensities in CH4, SiH4, GeH4 and SnH4

The effective bond charges (EBCs) method was applied in interpreting the in frared intensities of the v(3) and v(4) bands in CH4, SiH4, GeH4 and SnH4. The experimental intensity data used are from the works of Hiller and Stral ey for CH4 and of Coats, McKean and Steele for SiH4, GeH4 and SnH4. The exp erimental EBCs are compared with ab initio estimates obtained at different levels of theory. The effective X-H bond charges (X = C, Si, Ge, Sn) charac terise the polar properties of these bonds. Excellent linear relationship b etween the electrostatic potential derived charges at the heavy atoms and t he EBC values was found. (C) 2001 Elsevier Science B.V. All rights reserved .