Our method (parts 1-3) for estimating solvent effects on electronic spectra in media with strong solute-solvent interactions is extended to interpret the MLCT absorption spectrum of Ru2+(NH3)(5)-pyridine in dilute aqueous solution : it should be generally applicable to inorganic charge-transfer spectra. First, both ab initio MCSCF and INDO/S-CI methods are used to estimate the gas-phase electronic excitation energies and state charge distributions; second, Monte Carlo simulations are performed to determine the ground-state liquid structure; finally the solvent shift is evaluated based on the gas-phase charge distributions and the explicit ground state solvent structure : no arbitrarily adjustable parameters such as "cavity radii" are required. Several intermolecular potential surfaces are used to investigate the relationship between solvent shift and solvent structure, with the most reasonable structure determined by comparison with results simulated for dilute Ru2+- (NH3)(6) solution : for this complex, the inner solvent shell contained 13 water molecules which formed 18 hydrogen bonds to the ammonia ligands. The solvent shift calculated using various methods is -7500 +/- 1500 cm(-1), implying that the gas-phase transition energy should be 32000 +/- 1500 cm(-1), consistent, given the level of approximation used, with the INDO/S-CI and ab initio MCSCF predictions which range from 34 000 to 39 000 cm(-1). It is proposed that a method which is both practicable and reliable for calculations such as this is to use ab initio SCF ESP charges combined with Kollman’s force field as the intermolecular potential during the simulations and to use INDO/S-CI charges when evaluating solvent shifts.