Calculation of Infrared Intensities by the CNDO Method

Abstract

The CNDO method, an approximate self‐consistent molecular‐orbital theory, has been applied to the calculation of dipole‐moment derivatives M_j=(∂μ/∂S_j), where μ is the molecular dipole moment and S_j an appropriate symmetry coordinate. The theory is reasonably successful in calculating both the magnitudes and the signs of M_j for molecules composed of first‐row elements and/or hydrogen. The calculations can be understood on the basis of familiar ideas about the changes in atomic hydridization on the bending or stretching of bonds.