Popis: |
The symmetry-adapted-cluster configuration-interaction method is used to investigate the spectroscopic properties of 7Li2(A1Σ+u) over the internuclear distance ranging from 2.4a0 to 37a0. The complete potential energy curves are calculated at numbers of basis sets. All the ab initio calculated points are fitted to the analytic Murrell–Sorbie function and then employed to compute the spectroscopic constants. By comparison, the spectroscopic constants reproduced by the potential attained at D95(3df,3pd) are found to be very close to the experiments, and the values (Te, De, Re, ωe, ωeχe, αe and Be) are of 1.732 93 eV, 1.161 36 eV, 0.313 27 nm, 251.95 cm−1, 1.623 cm−1, 0.005 35 cm−1, and 0.490 cm−1, respectively. With the potential obtained at D95(3df,3pd), the totally 75 vibrational states are found when J = 0. The vibrational levels, the classical turning points and the inertial rotation constants of the first 68 vibrational states are calculated for the first time and compared with the available measurements. Good agreement is obtained. The centrifugal distortion constants of the first 32 vibrational states are also reported for the first time. The reasonable dissociation limit for 7Li2(A1Σ+u) is deduced using the calculated results at present. |