Mg2H2: New insight on the Mg-Mg bonding and spectroscopic study

V. Brites (1) , Marie Guitou (1) , Céline Léonard (1)

1 MSME - Laboratoire de Modélisation et Simulation Multi Echelle

The six dimensional potential energy surface of the electronic ground state (X) over tilde (1)Sigma(+)(g) of Mg(2)H(2) has been generated by the coupled-cluster approach with single, double and perturbative triple excitations [CCSD(T)] combined with the aug-cc-pCVTZ basis set for Mg atoms and the aug-cc-pVTZ basis set for the H atoms. The analytical representation of this surface was used in variational calculations of the rovibrational energies of Mg(2)H(2), Mg(2)D(2), and HMg(2)D for J = 0 and 1. For Mg(2)H(2), the rotational constant B(0) is computed to be 0.1438 cm(-1), and the fundamental anharmonic wavenumbers are calculated to be nu(1) = 1527.3 cm(-1) (Sigma(+)(g)), nu(2) = 275.3 cm(-1) (Sigma(+)(g)), nu(3) = 1503.6 cm(-1) (Sigma(+)(u)),nu(4) = 312.9 cm(-1) (Pi(g)), and nu(5) = 256.5 cm(-1) (Pi(u)). In addition, the electronic ground states of Mg(2)H, MgH(2), Mg(2), and MgH have been investigated in order to compute the bonding energies of Mg(2)H(2) and to explain the strength of the Mg-Mg bond in this tetra-atomic molecule. The nature of the low-lying excited states of Mg(2)H(2) is also studied. (C) 2011 American Institute of Physics. [doi:10.1063/1.3533962]

Domaines: Physique Classique [physics.class-ph]

V. Brites, Marie Guitou, Céline Léonard. Mg2H2: New insight on the Mg-Mg bonding and spectroscopic study. Journal of Chemical Physics, 2011, 134, pp.054314. ⟨10.1063/1.3533962⟩. ⟨hal-00692879⟩