Vibrational Intensities. XV. Error Treatment and Its Application to the Methyl Halides

Abstract

The estimation of statistical errors in the dipole‐moment derivatives, ∂p/∂Sⁱ, is described. Account is taken of contributions from random errors in the experimental intensity data, the intramolecular force constants, the molecular geometry, and the harmonic frequencies. It appears that generally the first two contributions are of similar importance and the second two negligible. As a detailed example of this treatment we have reworked the vibrational intensities of methyl fluoride, chloride, bromide, and iodide and their deuterium derivatives using new estimates of the normal coordinates. The calculated rotational contributions to the dipole‐moment derivatives with respect to symmetry coordinates have been corrected.