Abstract
THE development of an intermolecular potential energy function for simple molecules based solely on an investigation of properties arising from two-body interactions1 may prove more valuable than the alternative approach which considers also the properties of solids2. The latter approach involves the assumption of the pair-wise additivity of potential energy, the validity of which must be regarded as unproven. Unfortunately, the second virial coefficient, which is the most convenient two-body property to analyse, is not capable of defining a unique potential energy function3. However, recent low-temperature data provide a valuable test of the adequacy of potential energy functions and illustrate clearly the failure of many widely-used potentials4. Although some evidence points to a more complex form of the potential function, it seems appropriate to examine first simple two-term functions of the (nā6) type, which may be written: when rm is the separation of the molecular centres at the potential minimum. The collision diameter Ļ is related to rm by:
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Munn, R. J., J. Chem. Phys., 40, 1439 (1964).
Guggenheim, E. A., and McGlashan, M. L., Proc. Roy. Soc., A, 255, 456 (1960).
Keller, J. B., and Zumino, B., J. Chem. Phys., 30, 1351 (1959).
Fender, B. E. F., and Halsey, G. D., J. Chem. Phys., 36, 1881 (1962).
Myers, A. L., and Prausnitz, J. M., Physica, 28, 303 (1962).
Kihara, T., Rev. Mod. Phys., 25, 831 (1953).
Saxena, S. C., and Joshi, K. M., Indian J. Phys., 36, 422 (1962).
Poole, R. A. N., Saville, G., Herrington, T. M., Shields, B. D. C., and Staveley, L. A. K., Trans. Farad. Soc., 58, 1692 (1962).
Kerr, E. C., thesis, Ohio State Univ. (1957).
Thomaes, G., and van Steenwinkel, R., Nature, 193, 160 (1962).
Hirschfelder, J. O., Curtiss, C. F., and Bird, R. B., Molecular Theory of Gases and Liquids, 31 (J. Wiley and Sons, Inc., New York, 1954).
Graber, H. W., and Present, R. D., Phys. Rev. Lett., 9, 247 (1962).
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DYMOND, J., RIGBY, M. & SMITH, E. Intermolecular Potential Energy Functions for Simple Molecules. Nature 204, 678 (1964). https://doi.org/10.1038/204678a0
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DOI: https://doi.org/10.1038/204678a0
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