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Interatomic forces over a wide range of nuclear separations
Author(s) -
Robinson G.,
March N. H.,
Perrin R. C.
Publication year - 2009
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560050831
Subject(s) - bohr model , van der waals force , bohr radius , potential energy , atomic physics , virial coefficient , atom (system on chip) , interatomic potential , scattering , chemistry , lennard jones potential , pair potential , radius , range (aeronautics) , virial theorem , van der waals radius , physics , molecular dynamics , molecule , quantum mechanics , materials science , composite material , computer security , galaxy , computer science , quantum dot , embedded system
An interaction potential energy between rare gas atoms is set up which: (1) Reproduces the correct angular distribution for atomic scattering at high energies. (2) Fits the second virial coefficient and molecular orbital calculations at the smallest separations yet considered. (3) Fits the quantum mechanically calculated van der Waals constant. The most careful calculations we report are for Ne‐Ne interactions. The gas scattering data in the high energy regime (25‐100 kev) is shown to be fitted, to within experimental error, by either the Bohr or the Firsov potentials. This analysis gives information on the potential inside half a Bohr radius a 0 . The smallest distance at which molecular orbital calculations are available for Ne‐Ne, on the other hand, is 2.5 a 0 . A potential constructed by joining together forms appropriate for small and large nuclear separations is then used in molecular dynamical calculations of the liquid structure factor. The main features can be satisfactorily reproduced by a potential resembling a Lennard‐Jones potential in the bowl, but joining on to a much softer potential at small distances. Finally, some remarks are made on the change in the two‐body potential at large distances, in condensed matter, from that between rare gas atoms in a vacuum and the major differences for metal atom (eg. Li) interactions are stressed.