Repulsive Interaction Potentials between Rare-Gas Atoms. Heteronuclear Two-Center Systems

Abstract

A theoretical expression, previously applied only to homonuclear pairs of rare-gas atoms, has been used to calculate the interaction energies $U(R)$ for the corresponding heteronuclear two-center systems at inter-nuclear separations $R$ ranging from $0.01{a}_{0}$ to $\ensuremath{\sim}6.0{a}_{0} ({a}_{0}=0.529 \mathrm{\AA{}})$. These results are compared with: (a) empirical data; (b) other calculations; (c) the geometric-mean rule ${U}_{\mathrm{AB}}={({U}_{\mathrm{AA}}{U}_{\mathrm{BB}})}^{\frac{1}{2}}$; (d) the corresponding united-atom energies. With regard to (a) and (b), this comparison supports conclusions drawn previously from a study of the homonuclear pairwise interactions. That is, the present calculations, too, generally agree more closely with experiment than does either Bohr's screened Coulomb potential or Firsov's Thomas-Fermi type potential. Relation (c) is found to be satisfied, generally, to within a few percent. As for (d), calculations for the He-Ne and Ar-Kr systems indicate that, as $R\ensuremath{\rightarrow}0$, the electron energy of each system tends, approximately, to the appropriate empirical united-atom value. A similar study of other systems, including the light gases, metals, and certain diatoms, is in progress.

Keywords

Affiliated Institutions

• City College of New York US
• Brookhaven National Laboratory US

Related Publications