Eur. Phys. J. D 63, 351-358 (2011)
https://doi.org/10.1140/epjd/e2011-10706-3

Regular Article

Geometries and electronic structures of Ga₂Se₃, Ga₃Se₂ and their anions. Theoretical insights^*

¹ Department of Chemistry, University of Mauritius, Mauritius
² School of Chemical Sciences, Universiti Sains Malaysia, Malaysia
³ Department of Chemistry, University of Namibia, Namibia

^a e-mail: p.ramasami@uom.ac.mu

Received: 14 December 2010
Received in final form: 31 March 2011
Published online: 17 June 2011

Abstract

We hereby report a theoretical study on the equilibrium geometries, electronic structures and harmonic vibrational frequencies of Ga₂Se₃, Ga₃Se₂ and their anions. The ground and low-lying excited states of Ga₂Se, Ga₂Se₃, Ga₃Se and Ga₃Se₂ are studied at the B3LYP and/or MP2 and CCSD(T) levels in conjunction with 6-311+G(d) and 6-311+G(2df) one particle basis sets. Ga₂Se adopts the C_2v kite geometry while Ga₂Se₃ has a ‘V’ geometry. Ga₃Se has a three-dimensional ‘D_3h’ geometry and Ga₃Se₂ prefers the three-dimensional ‘C_2v’ structure. Electron detachment energies from the ground electronic states of the anions to several neutral states are reported and discussed. At CCSD(T)//MP2 level, the adiabatic electron affinity (AEA) of Ga₂Se₃ is calculated to be 3.23 eV when using the 6-311+G(2df) basis set and that of Ga₃Se₂ is 2.77 eV with the 6-311+G(d) basis set. The findings of this research are analyzed and compared with gallium oxide and sulfide analogues.