A theoretical study of ZnH2, a case of very strong Darling-Dennison resonance

Peter Botschwina (1) , Peter Sebald (2) , Hendrik Vennekate (2) , Rainer Oswald (2) , Hermann Stoll (3)

1 Institute of Physical Chemistry
2 Instiute of Physical Chemistry
3 Institute of Theoretical Chemistry

The metastable linear ZnH2 molecule in its X electronic ground state has been investigated by the coupled cluster method CCSD(T) in conjunction with a small-core pseudopotential for the zinc atom. Using the pieces of spectroscopic information for the most abundant isotopomer 64ZnH2, an accurate near-equilibrium potential energy function (PEF) has been constructed and used in variational calculations of rovibrational states and wave functions. The 1 and 2 band origins (in cm-1) for 64ZnH2 and 64ZnD2 (in parentheses) are predicted at 1886.4(1349.7) and 635.1(459.8), respectively. 64ZnH2 is characterized by strong Darling- Dennison and l-type rotational resonances. Various local perturbations are analyzed in detail, making use of calculated expectation values of the vibrational quantum number l. Einstein coefficients of spontaneous emission are predicted for several transitions.

Mots clés: Physical Sciences

Peter Botschwina, Peter Sebald, Hendrik Vennekate, Rainer Oswald, Hermann Stoll. A theoretical study of ZnH2, a case of very strong Darling-Dennison resonance. Molecular Physics, 2010, 108 (03-04), pp.487-499. ⟨10.1080/00268971003596151⟩. ⟨hal-00580690⟩