Phosphorescence spectra of tris( 2,2'-bipyridine) metal compounds, [ M( bpy)(3)](n+) , where M = Zn( II), Ru( II), Os( II), Rh( III), and Ir( III), were calculated using a harmonic oscillator approximation of adiabatic potential surfaces obtained by density functional theory ( DFT). Using the Huang-Rhys ( S) factors calculated by theoretical Franck-Condon analysis of T-1 and S-0 geometries, we successfully reproduced the emission spectra observed under various conditions by nonempirical calculations. The simulations of well-structured spectra of the Zn( II), Rh( III), and Ir( III) compounds confirmed that the emission originated from localized ligand-centered excited states with considerably distorted geometries of C-2 symmetry. The spectrum simulation revealed that the phosphorescence state of [ Ru( bpy)(3)](2+) was localized (MLCT)-M-3 both in a solution and a glass matrix. Furthermore, a highly resolved phosphorescence spectrum observed for [ Ru( bpy)(3)](2+) doped in a [ Zn( bpy)(3)]( ClO4)(2) crystal was reproduced well using the geometry of the localized (MLCT)-M-3 by assuming mode-specific broadening of low-frequency intramolecular vibrational modes. The deuterium effects of the electronic origins of the doped crystal observed by Riesen et al. were in excellent agreement with those predicted for the localized (MLCT)-M-3. However, the calculated satellite structures of the localized (MLCT)-M-3 involving bpy-h(8) in [ Ru( bpy-h(8))(3-x)( bpy-d(8))(x)](2+) ( x = 1,2) exhibited only the bpy-h(8) vibrational modes, inconsistent with the simultaneous appearance of both bpy-h(8) and bpy-h(8) modes in the observed spectra. A simulation on the basis of the geometry of the delocalized (MLCT)-M-3 was in reasonable agreement with an unresolved spectrum observed for a neat crystal of [ Ru( bpy)(3)]( PF6)(2), which is inconsistent with the assignments of localized (MLCT)-M-3 on the basis of the electronic origins. The inconsistency of the assignment on the basis of the adiabatic model is discussed in terms of vibronic coupling between the localized (MLCT)-M-3 states. The (MLCT)-M-3 state in [ Os( bpy)(3)](2+) seems to vary with the environment: a fully localized (MLCT)-M-3 in a solution, partially localized in a glass matrix, and delocalized in PF6 salts.