We apply a generalized numerical transfer-matrix method to the two-dimensional Ising ferromagnet in a nonzero field to obtain complex constrained free energies. Below T c certain eigenstates of the transfer matrix are identified as representing a metastable phase. The imaginary parts of the metastable constrained free energies are found to agree with a field-theoretical droplet model for a wide...

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...

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...

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...

In this paper, we discuss the experimental technique for real-time measurement of the lifetimes of the collision complex of bimolecular reactions. An application to the atom-molecule Br + I, reaction at two collision energies is made. Building on our earlier Communication [J. Chem. Phys. 95, 7763 ( 1991)], we report on the observed transients and lifetimes for the collision complex, the nature ...