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Long‐range interactions in the ground and two excited states of the HeH + molecule
Author(s) -
Piela Lucjan
Publication year - 1969
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.560030616
Subject(s) - multipole expansion , excited state , atomic physics , ground state , chemistry , dissociation (chemistry) , potential energy , bond dissociation energy , perturbation theory (quantum mechanics) , molecule , hydrogen atom , physics , quantum mechanics , organic chemistry , alkyl
The long‐range interaction energies for different dissociation products of the HeH + molecule have been calculated using the Rayleigh–Schrödinger perturbation theory up to the third order in the energy. The calculations were carried out for the ground state (He(ls 2 ) + H + ), the first excited state (H(ls) + He + (ls)) and the second excited state Π(H(2pπ) + He + (ls)). The unperturbed states correspond to the dissociation products denoted in parentheses. Assuming the overlap to be zero, expanding the interaction potential in the inverse powers of the internuclear distance R and using the familiarly known perturbation‐variational technique, the coefficients of various powers of R −1 in the energy expansion were evaluated. They correspond to different multipole‐multipole interactions. The potential energy curves of all three states under consideration were calculated for large values of R . Also calculated were the multipole polarizabilities of the hydrogen atom in the is and 2pπ states and of the helium atom in the ground state.