Potential-Energy Curves for CO and CO+

Abstract

Potential-energy curves for the X 1Σ+, A 1Π, I 1Σ−, a 3Π, a′ 3Σ+, d 3Δi, and e 3Σ− electronic states of CO and the X 2Σ+, A 2Πi, and B 2Σ+ electronic states of CO+ have been calculated using a modification of the Rydberg—Klein—Rees method. The curves for the a 3Π, d 3Δi, and A 2Πi states, which are intermediate between Hund's Cases (a) and (b), represent fictitious rotationless states calculated using the true Bv. Benesch and co-workers have shown theoretically that this representation is correct for such intermediate cases. The numerical results for the A 2Πi state presented here confirm their conclusions.

The band spectrum of carbon monoxide

“…Krupenie and Weissman [138] have recalculated these using a numerical method [271] There is close agreement with previous calculations [258]. Potential curves for the three observed states of CO + are included for the first time.…”

Fourier Grid Hamiltonian Method for calculating the Einstein coefficients, Franck–Condon factors, r-Centroids, average internuclear separations and radiative lifetimes for N2 and CO molecules

“…1. The computed eigenvalues for both the HH and RKR models are in good agreement with the experimental eigenvalues [43,44]. The agreement of our values with the experimental data from literature is very good especially for lower values of vibrational quantum numbers.…”

“…The computed and experimental vibrational eigenvalues of the X 1 and A 1 П electronic states of CO molecule are given in the Table S3 and Table S4. The difference between our computed eigenvalues and experimental values given by Weissman et al [44] are less than 1%. Tables S1-S4 are given in the supporting information.…”

“…The effectiveness of FGH method is in its speed and accuracy, once the potential energy surface is known accurately. The agreements of our eigenvalues with experimental eigenvalues [43,44] to within 2% are the true tests of the wide applicability of the FGH method. The differences of 1 to 20% in FCFs, r-centroids and Einstein coefficients are more due to the differences in the potentials (resulting from the differences in the numerical methods used by us and by Gilmore and Laher [34] and by Mumma et al [35]) and the derived vibrational wavefunctions obtained in the two works and not due to the inaccuracy of our calculations.…”

Ab initiocalculations of radiative transition probabilities in theX2Σ+andA2Π electronic states of CO+

“…About 70 per cent of these effects have been covered with the MCSCF wavefunctions, which account for only 30-35 per cent of the total valence shell correlation energy. In order to avoid errors of the calculated transition matrix elements due to the inadequacies of the theoretical potential energy functions, we have evaluated the vibrational wavefunctions with RKR potentials, which are available for both of the electronic states of CO + considered [23]. …”