Popis: |
Quadratic configuration interaction (QCISD) method has been used to optimize the possible ground-state structures of BH 2 and AlH 2 molecules. The results show that the ground state of BH 2 molecule has C 2v symmetry and is in the 2 A 1 state. The parameters of structure and the harmonic frequencies are R BH =0.1187nm, ∠HBH=128.7914°, D e =3.65eV,ν 1 (a 1 )=1020.103cm -1 ,ν 2 (a 1 )=2598.144cm -1 and ν 3 (b 2 )=2759.304cm -1 , respectively. The results also show that the ground state of AlH 2 molecule has C 2v symmetry and is in the 2 A 1 state. The parameters of structure and the harmonic frequencies are of R AlH =0.1592nm, ∠HAlH=118.095°, D e =2.27eV,ν 1 (a 1 )=780.81cm -1 ,ν 2 (a 1 )=1880.81cm -1 and ν 3 (b 2 )=1910.46cm -1 , respectively. The potential energy functions of BH 2 and AlH 2 have been derived from the many-body expansion theory. The potential energy functions describe correctly the configurations and the dissociation energies of the two ground-state molecules. Molecular reaction kinetics of BH+H and AlH+H based on the potential energy functions is discussed briefly. |