Accurate ab initio study of low-lying electronic states of phosphorus nitride radical     

王杰敏  孙金锋  施德恒 《海洋学报(英文版)》2010,29(11)

This paper employs the highly accurate valence internally contracted multireference configuration interaction method to investigate the potential energy curves (PECs) for the ground state (X¹Σ⁺) and two low-lying excited states (A¹Π and D¹Δ of phosphorus nitride (PN) radical with the correlation-consistent basis set, aug-cc-pV6Z, in the valence range. Relativistic effects are considered in these calculations. The spectroscopic constants of the X¹Σ⁺ and A¹Π states are calculated based on the PECs, and the results are in good accord with the available experimental data. The first 30 vibrational states for the A¹Π state and the first 40 vibrational states for the A¹Π state are determined when J=0. For each vibrational state, molecular constants G(υ), B(υ) and D(υ) are also attained.  相似文献   

Molecular constants of LiCl(X¹Σ⁺) and elastic collisions of two ground-state Cl and Li atoms at low and ultralow temperatures     

朱遵略  张小妞  寇素华  施德恒  孙金锋 《海洋学报(英文版)》2010,29(11)

Interaction potentials for LiCl(X¹Σ⁺) are constructed by the highly accurate valence internally contracted multireference configuration interaction in combination with a number of large correlation-consistent basis sets, which are used to determine the spectroscopic parameters (D₀, D_e, R_e, ω_e, _eχ_e, B_e and α_e. The potentials obtained at the basis sets, i.e., aug-cc-pV5Z-JKFI for Cl and cc-pV5Z for Li, are selected to study the elastic collision properties of Li and Cl atoms at the impact energies from 1.0×10^-12 to 1.0×10^-4 a.u. The derived total elastic cross sections are very large and almost constant at ultralow temperatures, and their shapes are mainly dominated by the s-partial wave at very low impact energies. Only one shape resonance can be found in the total elastic cross sections over the present collision energy regime, which is rather strong and obviously broadened by the overlap contributions of the abundant resonances coming from various partial waves. Abundant resonances exist for the elastic partial-wave cross sections until l = 22 partial waves. The vibrational manifolds of the LiCl(X¹Σ⁺) molecule, which are predicted at the present level of theory and the basis sets cc-pV5Z for Li and the aug-cc-pV5Z-JKFI for Cl, should achieve much high accuracy due to the employment of the large correlation-consistent basis sets.  相似文献