We report second and third virial coefficients for the system CO2-H2O, calculated via cluster integrals using quantitative molecular models taken from the literature. Considered models include (1) fits to highly accurate ab initio calculations of the potential energy surfaces, and (2) semi-empirical Gaussian Charge Polarizable Models (GCPM). Three-body effects are found to be essential for obta...

Photochemical reactions may be classified as adiabatic or as diabatic whether the chemical change occurs on the same potential energy surface or not. In the adiabatic cases deexcitation occurs either in the reactant (I) or in the product (II) while in the diabatic case it occurs in between them (III). The potential energy surfaces of polyatomic systems are discussed in relation to photochemistr...

Efficient electronic structure methods can be built around efficient tensor representations of the wavefunction. Here we first describe a general view of tensor factorization for the compact representation of electronic wavefunctions. Next, we use this language to construct a low-complexity representation of the doubles amplitudes in local second-order Møller-Plesset perturbation theory. We int...

We discuss recent progress in the calculation and identification of rotation-vibrational states of H3+ at intermediate energies up to 13,000 cm(-1). Our calculations are based on the potential energy surface of Cencek et al. which is of sub-microhartree accuracy. As this surface includes diagonal adiabatic and relativistic corrections to the fixed nuclei electronic energies, the remaining discr...

Depending on the initial energies, a proton transfer may proceed either via a saddle-point in a potential energy surface or by crossing from the reactants' to the products' valley before the saddle-point is reached. In the second path the analogy to weak-overlap electron transfers is pointed out. The present study is intended to unify previously divergent viewpoints, by showing how they are spe...

The laser excited, jet-cooled Ã2A′′ 2 − X̃2E′′ 1 electronic spectrum of the cyclopentadienyl radical yields detailed information about the vibronic structure of both its à and X̃ states. A straight-forward assignment of the à vibronic structure is presented. The X̃ state vibronic structure reveals a comprehensive picture of the Jahn-Teller distortion of its potential energy surface. The molecular ...

Ro-vibrational calculations on a recent ab initio potential energy surface for H: (W. Meyer et al., J. Chem. Phys. 84, 891 (1986)) are presented for the isotopomers H,_.D: (n = 0, 1, 2, 3). These calculations employ refinements recently developed for nuclear motion calculations and are thus of very high accuracy. The rotational levels with .I G 4 are fitted to standard vibrationrotation Hamilto...

long range Liesbeth M. C. Janssen, Gerrit C. Groenenboom, Ad van der Avoird, Piotr S. Żuchowski, and Rafał Podeszwa Theoretical Chemistry, Institute for Molecules and Materials (IMM), Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands Department of Chemistry, Durham University, South Road, DH1 3LE, United Kingdom Institute of Chemistry, University of Silesia, Szk...

We report six-dimensional quantum dynamical calculations of dissociative adsorption and associative desorption of the system H2/Pd(100) using an ab initio potential energy surface. We focus on rotational effects in the steering mechanism, which is responsible for the initial decrease of the sticking probability with kinetic energy. In addition, steric effects are briefly discussed. Typeset usin...