A simple approximation for the vibrational partition function of a hindered internal rotation

A simple formula is presented for calculating the approximate partition function of a hindered internal rotational mode of a polyatomic molecule. The formula gives useful accuracy over the whole range from harmonic oscillator to hindered rotator to free rotator.

[1]  J. D. Kemp,et al.  Hindered Rotation of the Methyl Groups in Ethane , 1936 .

[2]  Kenneth S. Pitzer,et al.  Energy Levels and Thermodynamic Functions for Molecules with Internal Rotation I. Rigid Frame with Attached Tops , 1942 .

[3]  K. Pitzer,et al.  Theoretical Pre‐Exponential Factors for Twelve Bimolecular Reactions , 1956 .

[4]  Jerome D. Swalen,et al.  Internal Rotation and Microwave Spectroscopy , 1959 .

[5]  H. Johnston Gas Phase Reaction Rate Theory , 1966 .

[6]  H. Johnston,et al.  Computed High‐Temperature Rate Constants for Hydrogen‐Atom Transfers Involving Light Atoms , 1966 .

[7]  D. L. Bunker,et al.  Monte Carlo Calculations. VI. A Re‐evaluation of the RRKM Theory of Unimolecular Reaction Rates , 1968 .

[8]  D. Truhlar Adiabatic Theory of Chemical Reactions , 1970 .

[9]  W. Hase The criterion of minimum state density in unimolecular rate theory. An application to ethane dissociation , 1976 .

[10]  Kazuhiro Ishida,et al.  The intrinsic reaction coordinate. An ab initio calculation for HNC→HCN and H−+CH4→CH4+H− , 1977 .

[11]  E. Grant,et al.  Dynamical effects in unimolecular decomposition: A classical trajectory study of the dissociation of C2H6. , 1978 .

[12]  Donald G. Truhlar,et al.  Criterion of minimum state density in the transition state theory of bimolecular reactions , 1979 .

[13]  John E. Adams,et al.  Reaction path Hamiltonian for polyatomic molecules , 1980 .

[14]  William H. Miller,et al.  Reaction Path Hamiltonian for Polyatomic Systems: Further Developments and Applications , 1981 .

[15]  K. Morokuma,et al.  Potential Energy Characteristics for Chemical Reactions , 1981 .

[16]  W. Hase,et al.  Thermal rate constant for H+CH3 → CH4 recombination. Comparison of quasiclassical trajectory and variational transition state theory , 1985 .

[17]  Michael Baer,et al.  Theory of chemical reaction dynamics , 1985 .

[18]  P. Pacey,et al.  Canonical variational transition state theory for a radical combination reaction on abinitio potential energy surfaces: H+CH3 , 1985 .

[19]  D. M. Hirst,et al.  Thermal Rate Constants for H + CH3 CH4 Recombination. II. Comparison of Experiment and Canonical Variational Transition State Theory , 1987 .

[20]  W. Hase,et al.  Transition states and rate constants for ion–molecule association. II. Li++(CH3)2O→Li+[(CH3)2O] , 1987 .

[21]  E. Aubanel,et al.  Flexible transition-state theory rate constants for the recombination reaction methyl + hydrogen atom .fwdarw. methane , 1989 .

[22]  A. Rauk,et al.  Structure and thermodynamic functions of the isopropyl radical: an ab initio study , 1990 .