Near-resonant vibration-to-vibration energy transfer in the NO+–N2 collisions

Abstract

First principles model calculations of the vibration-to-vibration (VV) energy transfer (ET) processes NO(+)(nu=1)+N(2)(nu=n-1)-->NO(+)(nu=0)+N(2)(nu=n)+(28.64n-14.67) cm(-1) and NO(+)(nu=n)+N(2)(nu=0)-->NO(+)(nu=n-1)+N(2)(nu=1)+(32.52(n-1)+13.97) cm(-1) for n=1-3 in the 300-1000 K temperature range are performed. The VV ET probability is computed for three mechanisms: (1) The charge on NO(+) acting on the average polarizability of N(2) induces a dipole moment in N(2) which then interacts with the permanent dipole moment of NO(+) to mediate the energy transfer. (2) The charge on NO(+) acting on the anisotropic polarizability of N(2) induces a dipole moment in N(2) which then interacts with the permanent dipole moment of NO(+) to mediate the energy transfer. (3) The dipole moment of NO(+) interacts with the quadrupole moment of N(2) to mediate the energy transfer. Because the probability amplitudes of the second and third mechanisms add coherently the ET probability for these two mechanisms is given as a single number. The probability of energy transfer per collision is in the 5 x 10(-3) range. The results of this calculation are compared with the available experimental data. This calculation should help quantify the role of NO(+) in the energy budget of the upper atmosphere.