Resonance Raman spectroscopy in the dissociative A band of nitrosyl chloride

Abstract

Ab initio potential energy surfaces, total absorption cross sections, and product quantum state distributions for the low-lying electronic states of N 2 O Resonance Raman spectra measured for ClNO photoexcited at 212.5, 219, and 222 nm produce evidence that the strong transition at the vacuum ultraviolet end of the merged A band system dominates to wavelengths as long as 222 nm. The spectral resolution is sufficient to enable definitive assignments of excited vibrational levels in the ground electronic state, several of which have not been previously observed. A curvilinear coordinate model of the ground state potential surface around the Franck-Condon region has been constructed. This model yields vibrational eigenvalues in excellent agreement with all known transitions.

Multimode wavelet basis calculations via the molecular self-consistent-field plus configuration-interaction method

“…30 For the bound levels we investigate, it is found that eigenvalues and eigenvectors are all converged tobetter than 0.0001 cm −1 using the intervals 0.8 Å ഛ r ഛ 1.6 Å, 1.5 Å ഛ R ഛ 3.5 Å, and −1 ഛ z ഛ 0 with inner scaling function bases of sizes 124, 200, and 124, respectively. 30 For the bound levels we investigate, it is found that eigenvalues and eigenvectors are all converged tobetter than 0.0001 cm −1 using the intervals 0.8 Å ഛ r ഛ 1.6 Å, 1.5 Å ഛ R ഛ 3.5 Å, and −1 ഛ z ഛ 0 with inner scaling function bases of sizes 124, 200, and 124, respectively.…”

“…[37][38][39][40] One appropriate example is given by nitrosyl chloride, for which dissociative resonance Raman experiments by Mackey et al 30 have extended the number of observed vibrational transitions to a total of 27 reaching up to 7000 cm −1 above the ground state. It is then important to be able to construct and evaluate vibrational models in one set of curvilinear coordinates or another, for which one may again use SCF-CI methods.…”

“…[26][27][28] These methods can be extended to other wavelet or multiwavelet families to restrict them to an interval. This is a model of the three-dimensional ͑3D͒ vibrations of nitrosyl chloride described in curvilinear Jacobi coordinates, 30 for which there are both kinetic and potential couplings between vibrational modes. As a new case, the "leastasymmetric," or symmlet, single-wavelet basis 24 is adapted to the interval and used in our second application.…”

Additions to the class of symmetric-antisymmetric multiwavelets: Derivation and use as quantum basis functions

“…The equilibrium values ͑r e , R e , z e ͒ and linear and nonlinear parameters are given in Mackey et al 28 Wavelet bases, despite having been constructed originally for Cartesian problems, can be used for each of the coordinates. The equilibrium values ͑r e , R e , z e ͒ and linear and nonlinear parameters are given in Mackey et al 28 Wavelet bases, despite having been constructed originally for Cartesian problems, can be used for each of the coordinates.…”

Regularity in highly excited vibrational dynamics of NOCl (X 1A′): Quantum mechanical calculations on a new potential energy surface

“…Recently, an extensive study was carried out using the resonance Raman experiment. 12 On the theoretical ground, many vibrational analyses have been performed. [13][14][15][16][17][18] Particularly, ab initio/empirical potential energy function study by Botschwina, Haertner, and Sawodney 13 is notable.…”