Knowledge Bank

Electric dipole moment functions of the electronic ground states of several diatomic molecules have been calculated using highly correlated multireference-configuration expansions. From these functions, Einstein transition probability coefficients of spontaneous emission and related quantities have been obtained. For the OH radical, the dependence of the dipole moment function on the atomic basis set and on the number and the structure of the reference configurations has been investigated extensively. Based on these tests, the present results are believed to be more accurate than previous theoretical and experimental data. Our transition probabilities differ significantly from earlier theoretical data published by $Mies,1$ which have often been used in the past. The molecular ions $OH-,OH+,HF+$, and $HCl+$ are predicted to be stronger IR emitters than the corresponding neutral molecules. The rotationless rates $A01$ of spontaneous emission are calculated to be 12.2, 137, 263, 618, and $217sec-1$ for $OH,OH-,OH+,HF+$, and $HCl+$, respectively.