Four-dimensional dipole moment surfaces and local mode vibrational band intensities of GeH4

The local mode vibrational band intensities of GeH4 were calculated employi ng four-dimensional dipole moment surfaces (DMS) and local mode potential e nergy surfaces. Two kinds of DMS were tested: purely ab initio DMS from cou pled cluster CCSD(T) calculations and effective DMS where selected higher-o rder terms in the former were optimized by fitting experimental intensities . Both DMS reproduce the intensities for transitions below 6500 cm(-1) wen. The effective DMS leads to better agreement for higher excitations and rep roduces the intensity anomaly in the fourth local mode manifold. (C) 2001 E lsevier Science B.V. All rights reserved.