Potential energy surfaces of ozone. I

Abstract

The cross section through the ground~state potential energy surface of ozone which contains the open minimum, the ring minimum, and the ring-opening reaction path, including the ringopening transition state, is determined through full-valence-space muiticonfiguration selfconsistent-field calculations. It is shown that, at a point on the ridge separating the openstructure basin from the ring-structure basin in C 2V symmetry, very close to the transition state, the ground-state surface connects with the lowest excited state surface of the same symmetry (IA 1)' This point is part of an intersection seam between these two IA I surfaces in C s symmetry. It is furthermore found that the upper state has its eqUilibrium structure very close to the transition state of the lower state. The quantitative data of all critical points are calculated. In addition, a ground-state potential energy surface cross section describing the detachment of an oxygen atom is determined. For several other states, C zv constrained and bond-length-optimized energy curves E(¢) are also reported.

Photodissociation of ozone at 193 nm by high-resolution photofragment translational spectroscopy

“…Imre and others performed a 2-D time-dependent calculation to generate the autocorrelation function, which they compared to results from resonance Raman experiments. [13,26,27] ring from of ozone, thought to lie slightly above the dissociation threshold; [31,18] no direct experimental evidence has yet been found for this species. Virtually all dynamical studies have focused on the fate of the molecule once prepared on the 1 B 2 surface.…”

“…Alternately, theoretical calculations find a conical intersection between the 6 state and the ground state, in the vicinity of the equilateral geometry. [18,20] This represents another distinct path to ground state products from the 6 s~rface. However, the calculations have not been sufficiently extensive to allow meaningful speculation about the fact that so much of the available energy for this channel appears in vibration.…”

“…There exists an extensive body of theoretical work on ozone, both ab initio calculations [15][16][17][18][19][20][21][22] and dynamical studies. [13][14][15][23][24][25][26][27][28] Owing to its electronic complexity (it is effectively a spin-paired biradical), ozone represents a serious challenge to Hartree-Fock methods.…”

Accurate ab initio potential energy curve of F2. I. Nonrelativistic full valence configuration interaction energies using the correlation energy extrapolation by intrinsic scaling method

“…2-11͒, to name but a few important properties, depend on accurate descriptions of surface features, such as transition states, reaction paths, conical intersections, etc. [12][13][14][15][16][17][18][19][20][21][22][23] In many instances, such accurate descriptions require the use of many-electron ab initio wavefunctions, and our discussion is limited to these. In this context, the full configuration interaction ͑FCI͒ method 24,25 has as yet remained the benchmark approach because of its variational attributes.…”

O2(a1Δg) + Mg, Fe, and Ca: Experimental kinetics and formulation of a weak collision, multiwell master equation with spin-hopping

“…This appears to derive from the fact that triplet isomerisation from OCaO to CaO 2 , despite the fact that it appears overall symmetry allowed, is forbidden based on the orbital occupation patterns within the different geometries. 42 where both the open and cyclic forms have the same overall symmetry, but interconversion is symmetry forbidden owing to the orbital occupation pattern. In C s symmetry, a 1 and b 2 orbitals (in C 2v ) become a orbitals, and what were b 1 and a 2 orbitals become a orbitals.…”