Einstein coefficients for diatomic molecules

Re-examination of current semiempirical methods for computing Einstein coefficients for diatomic molecules has resulted in the development of a new technique for predicting infrared transition probabilities. The method uses a nonlinear transformation of existing polynomial dipole expressions with the subsequent application of appropriate boundary conditions to arrive at improved dipole curves. The transition probabilities predicted for HF are found to yield the most consistent agreement with the available experimental data when compared with existing results. Reanalysis of experimental data by the use of the new transition probabilities yields an HF(v) distribution for the reaction, H + F2 → HF(v) + F, 0 ≤ v ≤ 9, that is in better agreement with independent theoretical predictions than the uncorrected distribution. The method has also been used to compute the Einstein A coefficients of DF, HCl, and DCl.