A Geometric Visualization of Normal-Coordinate Transformations. Application to the Calculation of Bond-Moment Parameters and Force Constants

Abstract

Two methods are given for factoring the normal‐coordinate transformation into transformations easier to visualize geometrically. The relations thus obtained have been used in a simple one‐dimensional representation of the force constants and bond‐moment parameters for CF₄ and C₂F₆. By this means one can easily investigate the existence of force fields which will bring the bond‐moment parameters for CF₄ and the A_2u class of C₂F₆ into agreement. A further application to the problem of choosing the best force constants for a pair of isotopic molecules is shown for the B_3u class of ethylene.