ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
The nonadditive interactions in the Ar2Cl− cluster are studied using the supermolecular Møller–Plesset perturbation theory in conjunction with the perturbation theory of intermolecular forces. The three-body effect is rigorously dissected into fundamental nonadditive components; the exchange, the induction, and the dispersion. All three terms are important in describing nonadditivity in this cluster. The exchange nonadditivity is further divided into two terms; ES3, the electrostatic interaction between the Cl− and Ar2 subunits due to the appearance of an "exchange-quadrupole'' moment on Ar2 [Cooper and Hutson, J. Chem. Phys. 98, 5337 (1993)], and the exchange counterpart of ES3, the X3 term. ES3 term is modeled analytically using the charge-quadrupole electrostatic term. The induction nonadditivity is approximated as an interaction of induced dipoles on two Ar atoms. The three-body dispersion term is fitted to the dipole–dipole–dipole plus dipole–dipole–quadrupole expressions. The sum of all three analytical terms reproduces well the ab initio three-body potential in the region of the trimer minimum and beyond. Possible improvements in the analytical representation are also discussed. © 1995 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.469642
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