Femtosecond time-resolved velocity map imaging experiments are reported on several vibronic levels of the second absorption band (B-band) of CH3I, including vibrational excitation in the ν2 and ν3 modes of the bound R1(E) Rydberg state. Specific predissociation lifetimes have been determined for the 20 and 3 1 0 vibronic levels from measurements of time-resolved I*( P1/2) and CH3 fragment image...

The cumulative reaction probability ~CRP! has been calculated for the H21OH↔H2O1H in its full dimensionality by using the centrifugal sudden ~CS! approximation for J.0. The Boltzmann average of the CRP provides the most accurate thermal rate constant to date for the title reaction on the Walch, Dunning, Schatz, Elgersma ~WDSE! potential energy surface ~PES!. It is found that the theoretical rat...

A variant of a new empirical method, enables one fo express a collinear triaromic potential energy surface as a Family of Morse curves along “natural” bond order coordinates orthogonal to the reaction coordinate. The procedure depends on a single adjustable parameter which is related to the barrier-s height. Because an analytical expression for the number of vibrational states of a Morse oscill...

In the present paper we report on an analysis of the fine structure of the first excited quartet T2g of Mn4+ ions which occupy the octahedral site in the Cs2GeF6 host crystal. The dynamic T2g⊗ (eg + t2g) Jahn–Teller effect is considered in details, including the Ham effect of the reduction of the spin-orbit splitting and displacements of the ligands due to the combined effect of the a1g and eg ...

This article describes a quantum mechanical reactive scattering program for atom–diatom chemical reactions that we have written during the past several years. The program uses a coupled-channel hyperspherical coordinate method to solve the Schrödinger equation for the motion of the three nuclei on a single Born–Oppenheimer potential energy surface. It has been tested for all possible deuterium-...

The cumulative reaction probability is calculated for the H,+OH+H+H,O reaction in its full (six) dimensionality for total angular momentum J=O. The calculation, which should give the (numerically) exact result for the assumed potential energy surface, yields the cumulative reaction probability directly, without having to solve the complete state-to-state reactive scattering problem. Higher angu...

Numerical studies are providing novel information on the physical processes associated to physical aging. The process of aging has been shown to consist in a slow process of explorations of deeper and deeper minima of the system potential energy surface. In this article we compare the properties of the basins explored in equilibrium with those explored during the aging process both for sudden t...

The aim of this study was to analyse the dynamics of O(D)þH2/D2 reactions using quasiclassical trajectory calculations on a double-valued potential energy surface for H2O. Produced on the photodissociation of stratospheric ozone, the excited oxygen atom is a highly reactive species whose chemistry plays a key role in the ozone depletion cycle. In order to make comparisons with experiment, we st...

The equilibrium structure and potential energy surface of dilithium monoxide, Li2O, have been determined from large-scale ab initio calculations using the coupled-cluster method, CCSD~T!, with basis sets of doublethrough quintuple-zeta quality. The effects of core–electron correlation on the calculated molecular parameters were investigated. The vibrational–rotational energy levels of the LiOLi...

We locate putative global minima for (C60)N clusters modelled by the potential of Pacheco and Prates-Ramalho up to N=105. These minima are based on icosahedral packing up to N=15, but above this size the lowest-energy structures are decahedral or close-packed. Although structures based on the 98-molecule Leary tetrahedron, which have been inferred from experiment, are not lowest in energy for t...