用CCSD(T)方法计算基态SH和SD的光谱常数(英文)

CCSD(T)calculations of spectroscopic constants for the ground states of SH and SD

利用CCSD(T)方法和系列相关一致基cc-pVXZ及aug-cc-pVXZ(X=D,T,Q,5)对SH和SD分子的基态平衡几何,谐振频率和离解能进行了优化计算.利用优选出的CCSD(T)/aug-cc-pV5Z方法对SH和SD的基态进行单点能计算,并将计算结果拟合成了Murrell-Sorbie函数.利用得到的解析势能函数,计算了SH和SD的其余3个光谱常数(ω_ex_e,α_e和B_c),结果表明:除SD的ω_ex_e值外,其余结果均与实验值符合得相当好,但计算得出的ω_ex_e值与推导出的值25.134 cm^(-1)符合得很好.

The geometries, harmonic frequencies and dissociation energies of S H（X2П） and SD（X2П） are calculated by using CCSD（T） method in combination with the correlation-consistent basis sets cc- pVXZ and aug-cc-pVXZ（X= D, T, Q,5） . Then the analytical potential energy curves for the two species are calculated by employing the most accurate method CCSD（T）/ aug-cc-pV5Z and are fitted into the analytic Murrell-Sorbie functions. Subsequently the spectroscopic parameters are evaluated from the constructed potential energy functions. The calculated spectroscopic parameters show a good accord with the recent experiments except the ωexe of SD（X2П）. But the ωexe value for SD（X2П） is close to the deduced value of 25. 134cm-1.