Vibrational frequencies and spectroscopic constants for 1～3A' HNC and 1～3A' HOC～+ from high-accuracy quartic force fields

摘要

The spectroscopic constants and vibrational frequencies for the 1～3A' states of HNC, DNC, HOC～+, and DOC～+ are computed and discussed in this work. The reliable CcCR quartic force field based on high-level coupled cluster ab initio quantum chemical computations is exclusively utilized to provide the anharmonic potential. Then, second-order vibrational perturbation theory and vibrational configuration interaction methods are employed to treat the nuclear Schr?dinger equation. Second-order perturbation theory is also employed to provide spectroscopic data for all molecules examined. The relationship between these molecules and the corresponding 1～3A' HCN and HCO～+ isomers is further developed here. These data are applicable to laboratory studies involving formation of HNC and HOC～+ as well as astronomical observations of chemically active astrophysical environments.