Theoretical study of HBeO

A. Zaidi (1) , S. Lahmar (2) , Z. Ben Lakhdar , P. Rosmus , Gilberte Chambaud

1 LCT - Laboratoire de Chimie Théorique
2 RMND - Régulations métaboliques, nutrition et diabètes

Using multi-reference configuration interaction (MRCI) and coupled-cluster RCCSD(T) ab initio methods three-dimensional X(2)Pi potential energy surfaces (PES) have been generated for the X(2)Pi and A(2)Sigma(+) states of HBeO. The two components of the X(2)Pi electronic ground state form a linear-linear Renner-Teller pair. The HBeO structure is calculated to lie 11,917 cm(-1) above the BeOH isomer. A barrier on the A' PES of 10,920 cm(-1) relative to the HBeO minimum does not permit a spontaneous rearrangement. From variational Renner-Teller calculations the rovibronic levels of the X(2)Pi state of the HBeO radical have been evaluated for J = 1/2 and J = 3/2. The eigenstates can not be unequivocally assigned by harmonic quantum numbers due to anharmonic resonances involving all three vibrational modes. In contrast with previous studies A(2)Sigma(+) state is calculated above the X(2)Pi (T-e = 9389 cm(-1)). For some higher doublet and quartet states of BeOH and HBeO, MRCI vertical electronic transition energies are reported. (c) 2005 Elsevier B.V. All rights reserved.

Domaines: Biochimie, Biologie Moléculaire

A. Zaidi, S. Lahmar, Z. Ben Lakhdar, P. Rosmus, Gilberte Chambaud. Theoretical study of HBeO. Chemical Physics, 2006, 321 (1-2), pp.41--47. ⟨10.1016/j.chemphys.2005.07.034⟩. ⟨hal-00693774⟩