title: Photodissociation of N2O: potential energy surfaces and absorption spectrum.
abstract: The ultraviolet photodissociation of N(2)O is studied by wave packet calculations using global three-dimensional potential energy surfaces for the two lowest (1)A' states. The incorporation of all internal degrees of freedom in the dynamics calculations is essential for a realistic treatment. The room-temperature absorption cross section is well reproduced, including the weak vibrational structures. Classical periodic orbits show that the latter can be attributed to large-amplitude NN stretch motion combined with strong excitation of the bend. Weakening of the NN bond toward the N + NO channel is the necessary prerequisite. The temperature dependence of the calculated cross section is significant, as expected for a dipole-forbidden transition of a linear molecule; but it is not as strong as observed experimentally [G. S. Selwyn and H. S. Johnston, J. Chem. Phys. 74, 3791 (1981)]. This shortcoming is due to an apparent underestimation of the (0,1,0) hot band absorption. On the other hand, the calculations yield reasonable predictions of the ratios of bending-state resolved absorption cross sections, σ(0, 1, 0)∕σ(0, 0, 0) and σ(0, 2, 0)∕σ(0, 0, 0), measured at 204 nm [H. Kawamata et al. J. Chem. Phys. 125, 133312 (2006)].
authors.affiliation: Max-Planck-Institut für Dynamik und Selbstorganisation, D-37073 Göttingen, Germany. rschink@gwdg.de
authors.forename: R
authors.initials: R
authors.lastname: Schinke
mesh_terms: D009609:Nitrous Oxide / Q000737:chemistry*; D055668:Photochemical Processes; D011789:Quantum Theory; D013056:Spectrophotometry, Ultraviolet; D013499:Surface Properties
chemical_list: D009609:Nitrous Oxide