THE DIPOLE-MOMENT AND INFRARED TRANSITION STRENGTHS OF NITRIC-OXIDE

The electric dipole moment function for NO(X (II)-I-2) is determined b y nonlinear least-squares analysis of experimental data, including pre viously reported (Delta upsilon = 2)/(Delta upsilon= 1) transition bra nching ratios for upsilon' less than or equal to 13. Polynomial fits t o the dipole moment function are determined over the range of internuc lear separation from 0.97 to 1.50 Angstrom. The fitted dipole moment f unctions agree well with previous ab initio predictions, but differ so mewhat at the larger internuclear separations. The observed dipole mom ent functions are used to compute rotationless Einstein coefficients f or Delta upsilon = 1-4 vibrational transitions with upsilon'less than or equal to 20, The absolute Delta upsilon = 1 and Delta upsilon =2 Ei nstein coefficients are well determined by this analysis, especially f or upsilon'less than or equal to 12. The results provide a firm basis for determinations of vibration-rotation emission intensities of NO(X (II)-I-2) in high-temperature or nonequilibrium chemiexcitation system s'. (C) 1998 American Institute of Physics.