Vibrationally averaged dipole moments of methane and benzene isotopologues

摘要: DFT-B3LYP post-Born-Oppenheimer (finite-nuclear-mass-correction (FNMC)) calculations of vibrationally averaged isotopic dipole moments methane and benzene, which compare well with experimental values, are reported. For methane, in addition to the principal vibrational contribution molecular asymmetry, FNMC accounts for surprisingly large Born-Oppenheimer error about 34% moments. This unexpected result is explained terms concurrent electronic contributions. The calculated moment C6H3D3 twice as measured C6H5D. Computational progress advanced concerning applications larger systems choice appropriate basis sets. simpler procedure performing averaging on level then adding evaluated at equilibrium distance shown be appropriate. Also, set made by heuristic analysis physical behavior systems, instead comparison experiments.