The Normal Vibrations of Polyatomic Molecules as Treated by Urey-Bradley Field

Abstract

A method of setting up the vibrational secular equation for polyatomic molecules of ``Urey-Bradley field'' type is described. By this method the vibration frequencies of CCl4, CBr4, CH4, CD4, CCl3Br, CCl2Br2, CClBr3, CCl3H, CCl2H2, CClH3, CCl3D, CCl2D2, CClD3, CH3D, CH2D2, and CHD3 molecules have been calculated. The 102 fundamental frequencies calculated using 28 distinct force constants are in satisfactory agreement with the observed, with a mean deviation of 1.4 percent.