Comment on the classical theory of the rate of isomerization J. Chem. Phys. 97, 943 (1992); 10.1063/1.463197 Intramolecular energy transfer in the HNC/HCN isomerization reaction: Quasiclassical state specific isomerization rates controlled by localized potential featuresWe report the results of calculations, using classical mechanics, of the rate of the isomerization reaction HCN+-+CNH. The three purposes of the calculations are (i) to test whether or not the Zhao-Rice approximate version of the Davis-Gray theory provides an accurate description of the rate of isomerization when there is a large scale atomic rearrangement; (ii) to determine if the quasi-two-dimensional reaction path representation of dynamical evolution on a multidimensional potential energy surface preserves the major features of the phase space mappings in two dimensions that are the key features of the Davis-Gray formulation of unimolecular reaction rate theory; and (iii) to determine if the reaction path representation is useful when the energy of the system is considerably greater than that along the minimum energy path. We find that both the Zhao-Rice (ZR) and the reaction path calculations of the isomerization rate constant are in reasonable agreement with the rate constant estimated from trajectory calculations; the ZR rate constant is about a factor of 2 smaller, and the reaction path rate constant is about a factor of 2 larger, than that obtained from trajectory calculations. For the few data points available, the energy dependence of the ZR rate constant agrees very well with that obtained from trajectory calculations. The energy dependence of the reaction path rate constant is uniformly accurate over the range we have studied, but is in moderately good agreement with the values obtained from the trajectory studies. We conclude that the reaction path representation remains useful even when the energy of the reacting system is considerably greater than that along the minimum energy path.

We report an intensive graduate teaching assistant (GTA) training program developed at The University of Chicago. The program has been assessed and has been successful in preparing GTAs for effective discussion and laboratory teaching for both general and organic chemistry. We believe that this training program can provide insightful information to benefit other similar GTA training programs in the future.

This paper describes a quantitative comparison of the predicted and observed structure in the liquid-vapor interface of a metal. We report the results of a theoretical study of the structure of the liquid-vapor interface of Ga, based on self-consistent quantum Monte Carlo simulations using a pseudopotential representation of the electron-ion and the ion-ion interactions. The single-particle density distribution along the normal to the interface is predicted to display stratification, with a spacing of about an atomic diameter and the amplitude of the density oscillations decaying to zero after about a four-layer penetration into the bulk liquid. The pair structure function in the plane of the liquid-vapor interface is predicted to be essentially the same as that in the bulk liquid. The qualitative and quantitative character of these predictions are in very good agreement with the results of recent experimental studies. ͓S1063-651X͑97͒08912-5͔

Theoretical analysis for the determination of surface composition in molten Ga-Bi metal alloys by rare gas scattering J. Chem. Phys. 119, 9842 (2003); 10.1063/1.1615958 Erratum: "The structure of the liquid-vapor interface of a gallium-tin binary alloy" [J. We report the results of self-consistent quantum Monte Carlo simulations of the structure of the liquid-vapor interface of a dilute alloy of Bi in Ga. The results of the simulations are shown to be in good agreement with the results of experimental studies of the structure of the liquid-vapor interface of such an alloy reported by Lei, Huang, and Rice ͓J. Chem. Phys. 104, 4802 ͑1996͒, who determined the longitudinal density distribution͔ and by Flom et al. ͓Science 260, 332 ͑1993͒, who determined the transverse pair structure function͔.

We present the results of self-consistent quantum Monte Carlo simulations of the structures of the liquid-vapor interfaces of alkali metals ͑Na, K, Rb, Cs͒ using a modified semiempirical empty-core model potential. The purpose of this investigation is to simplify the analysis of inhomogeneous metals sufficiently to permit qualitative inferences to be drawn about the properties of families of metals. Both electronic and ion density profiles along the normal to the surface show oscillations in the liquid-vapor transition zone. These oscillations closely resemble those found in previous simulation studies of the liquid-vapor interfaces of alkalis, based on sophisticated nonlocal model potentials. Because of its semianalytical representation, the model potential used in this paper allows considerable simplification in the computational scheme relative to the effort involved in the previously published simulations. We find liquid Na, K, Rb, and Cs to exhibit similar surface layering. Moreover, our results suggest the existence of a corresponding states representation of the properties of this class of metals. We expect this new analysis will be useful in predicting the qualitative properties of the surface structures of a broad range of pure liquid metals.