A tight-binding total-energy (TBTE) method has been developed to interpolate between firstprinciples results describing the dissociation of molecules at surfaces. The TBTE scheme requires only a relatively small number of ab initio energies as input and gives a reliable global representation of the ab initio potential energy surface to within 0.1 eV accuracy compared to the ab initio results. T...

Dissociation and doubly differential cross sections are calculated for N1N2 at near-threshold collision energies using a semiclassical wave packet method in which the vibrational motion of the molecule is treated quantum mechanically and the rotational and translational motions are treated classically. A three-bodied London–Eyring–Polanyi–Sato potential energy surface is used and results compar...

Dissociative photodetachment ~DPD! of the molecular anion HOCO is used to probe the potential energy surface for the OH1CO→H1CO2 reaction. The HOCO anion, formed by electron impact on an expansion of CH41N2O1CO, is characterized for the first time in these experiments by photoelectron spectroscopy and photoelectron angular distribution measurements. Photodetachment of HOCO is found to produce H...

0009-2614/$ see front matter 2008 Elsevier B.V. A doi:10.1016/j.cplett.2008.05.043 * Corresponding author. Fax: +1 305 348 3772. E-mail address: [email protected] (A.M. Mebel). Ab initio G3(MP2,CC)//B3LYP/6-311G calculations have been performed to investigate the C2H + C6H6 and C4H3 + C4H4 reactions on the C8H7 potential energy surface. The results demonstrate that C2H reacts with benzene without ...

Topological characteristics of multidimensional potential energy surfaces are explored and the full conformation space is mapped on the set of local minima. This map partitions conformation space into energy-dependent or temperature-dependent ‘‘attraction basins’’ and generates a ‘‘disconnectivity’’ graph that reflects the basin connectivity and characterizes the shape of the multidimensional s...

Classical trajectory calculations for the unimolecular dissociation of nonrotating H2O, DHO, and MuHO are reported for different distributions of energy among the three vibrational normal modes. The calculations employ a realistic energy-switching potential energy surface for the electronic ground state of the water molecule. It is found that the unimolecular decay rates vary with the vibration...

Thermally driven chemistry as well as materials’ functionality are determined by the potential energy surface of a systems electronic ground state. This makes the potential energy surface a central and powerful concept in physics, chemistry and materials science. However, direct experimental access to the potential energy surface locally around atomic centers and to its long-range structure are...

Using an ab initio approach involving a non-empirical pseudopotentials for Na and Rb atoms, the adiabatic potential energy curves of 26 electronic states of NaRb ionic molecule dissociating up to Na(4p) + Rb and Na + Rb(7s) have been investigated. Their molecular spectroscopic constants have been derived and compared with the available theoretical works. Furthermore, the transition dipole momen...

The reaction path is an important concept of theoretical chemistry. We employ the definitions of the intrinsic reaction coordinate (IRC), the gradient extremal (GE), and the Newton trajectory (NT). The usual imagination in chemistry is that a minimum energy path is in a convex region of the potential energy surface. We describe different schemes of convexity to handle the situation. It comes ou...

Femtosecond ~fs! dynamics of reactions of cyclic ethers, symmetric and asymmetric structures, are reported. The diradical intermediates and their b-cleavages, which involve simultaneous C-C, C-H s-bond breakage and C-O, C-C p-bond formation, are observed and studied by fs-resolved mass spectrometry. To compare with experiments, we present density functional theory calculations of the potential ...