Emission, excitation, and vibrational spectra of [Ph4P][Ta(CO)(6)] are reported. The emission spectrum is assigned to a ligand field transition and contains a well-resolved vibrational progression in the symmetric Ta-C stretching normal mode. A second progression at longer wavelength is separated from the first by an energy that superficially does not appear to correspond to a vibrational mode. The spectra are interpreted in terms of Herzberg-Teller (H-T) coupling of the forbidden ligand field state with the fully allowed tantalum-to-carbonyl charge-transfer excited-state mediated by asymmetric t(1u) normal modes. The H-T coupling is treated by using a coordinate-dependent transition dipole moment that is zero at the equilibrium internuclear geometry but becomes nonzero along appropriate asymmetric normal coordinates. The coordinate dependence of the transition dipole moment is illustrated by using simple overlap considerations. Quantitative calculations of the spectra are carried out using the time-dependent theory of electronic spectroscopy and the coordinate-dependent transition dipole. The emission spectrum originates from a single excited electronic state with a single origin but two H-T false origins. Changes of the Ta-C and C-O bond lengths in the emitting excited electronic state are calculated and discussed. Alternative interpretations of the spectrum based on two emitting molecules, sites, or excited states are eliminated by excitation spectroscopy and by temperature, lifetime, and solvent dependence studies of the emission.