用CCSD(T)方法计算基态SH和SD的光谱常数(英文)

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.

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

The geometries, harmonic frequencies and dissociation energies of SH(X2 Π) and SD(X2Π) are calculated by using CCSD(T) method in combination with the correlation-consistent basis sets ccpVXZ and aug-ee-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 ωeχe of SD(X2 Π). But the ωeχe value for SD(X2 Π) is close to the deduced value of 25. 134cm-1.