Modified statistical method for intermolecular potentials. Combining rules for higher van der Waals coefficients

A modification of the Gordon‐Kim statistical method for calculating intermolecular potentials is presented, discussed, and shown to give a reasonable estimate of the whole potential curve for both like and unlike pairs of noble gas atoms. Rae's correction to the exchange energy is used, but double counting of the correlation energy is avoided by using the van der Waals energy in lieu of the statistical correlation energy at large internuclear separations. Simple but apparently reliable combining rules for the van der Waals C8 and C10 coefficients are derived and tested. Calculated interatomic potentials are given for all pairs of noble gas atoms.

[1]  A. C. Wahl,et al.  Theoretical Study of the van der Waals Forces in Alkali-Noble-Gas Systems , 1971 .

[2]  A. Fetter,et al.  Quantum Theory of Many-Particle Systems , 1971 .

[3]  W. Byers Brown,et al.  Recent Developments in Perturbation Theory , 1964 .

[4]  D. A. Mcquarrie,et al.  Upper and Lower Bounds to Long‐Range Intermolecular Potentials , 1969 .

[5]  W. J. Meath,et al.  Charge‐Overlap Effects. Dispersion and Induction Forces , 1969 .

[6]  J. Hirschfelder,et al.  Perturbation theories for the calculation of molecular interaction energies. I. General formalism , 1973 .

[7]  E. A. Mason,et al.  Estimation of dipole‐quadrupole dispersion energies , 1973 .

[8]  C. F. Curtiss,et al.  Molecular Theory Of Gases And Liquids , 1954 .

[9]  R. T. Pack.  Upper and lower bounds to van der Waals force constants from half-integer oscillator strength sums , 1972 .

[10]  H. Schaefer,et al.  Interatomic correlation energy and the van der Waals attraction between two helium atoms , 1971 .

[11]  A. Lesk.  Lower bound to the long‐range interaction energy of two identical rare gas atoms in the restricted Hartree‐Fock approximation , 1973 .

[12]  J. Linnett,et al.  The Energy of Interaction between Two Hydrogen Atoms , 1950 .

[13]  D. Herschbach,et al.  Combination Rules for van der Waals Force Constants , 1970 .

[14]  John C. Slater,et al.  Quantum Theory of Molecules and Solids , 1951 .

[15]  A. Rae.  A theory for the interactions between closed shell systems , 1973 .

[16]  H. Kramer.  Inequalities for van der Waals Force Constants and Quantum Mechanical Sums , 1970 .

[17]  G. Starkschall,et al.  Calculation of Coefficients in the Power Series Expansion of the Long‐Range Dispersion Force between Atoms , 1972 .

[18]  P. W. Langhoff,et al.  Comparisons of Dispersion Force Bounding Methods with Applications to Anisotropic Interactions , 1971 .

[19]  N. Kestner,et al.  Multipole polarizabilities and London dispersion forces between neon and helium atoms using double perturbation theory , 1973 .

[20]  J. Toennies.  On the validity of a modified Buckingham potential for the rare gas dimers at intermediate distances , 1973 .

[21]  H. Margenau.  Van der Waals Potential in Helium , 1939 .

[22]  A. D. McLean,et al.  Accurate calculation of the attractive interaction of two ground state helium atoms , 1973 .

[23]  R. Gordon,et al.  Theory for the Forces between Closed‐Shell Atoms and Molecules , 1972 .

[24]  B. Schneider.  Study of the potential curves of xenon with other rare gas atoms , 1973 .

[25]  A. C. Wahl,et al.  Single‐Configuration Wavefunctions and Potential Curves for the Ground States of He2, Ne2, and Ar2 , 1967 .