EINSTEIN A COEFFICIENTS AND OSCILLATOR STRENGTHS FOR THE A~2Π-X~2Σ~+ (RED) AND B~2Σ~+-X~2Σ~+ (VIOLET) SYSTEMS AND ROVIBRATIONAL TRANSITIONS IN THE X~2Σ~+ STATE OF CN

摘要

Line strengths have been calculated in the form of Einstein A coefficients and f-values for a large number of bands of the A~2Π-X~2Σ~+ and B~2Σ~+-X~2Σ~+ systems and rovibrational transitions within the X~2Σ~+ state of CN using Western's pgopher program. The J dependence of the transition dipole moment matrix elements (the Herman-Wallis effect) has been taken into account. Rydberg-Klein-Rees potential energy functions for the A~2Π, B~2Σ~+, and X~2Σ~+ states were computed using spectroscopic constants from the A~2Π-X~2Σ~+ and B~2Σ~+-X~2Σ~+ transitions. New electronic transition dipole moment functions for these systems and a dipole moment function for the X~2Σ~+ state were generated from high level ab initio calculations and have been used in Le Roy's level program to produce transition dipole moment matrix elements (including their J dependence) for a large number of vibrational bands. The program pgopher was used to calculate Einstein A coefficients, and a line list was generated containing the observed and calculated wavenumbers, Einstein A coefficients and f-values for 290 bands of the A~2Π-X~2Σ~+ transition with v' = 0-22, v" = 0-15, 250 bands of the B~2Σ~+-X~2Σ~+ transition with v' = 0-15, v" = 0-15 and 120 bands of the rovibrational transitions within the X~2Σ~+ state with v = 0-15. The Einstein A coefficients have been used to compute radiative lifetimes of several vibrational levels of the A~2Π and B~2Σ~+ states and the values compared with those available from previous experimental and theoretical studies.