Transforming this matrix using the matrix C of eigenvectors of the exciton Hamiltonian, the transition dipole moments between the vibrational states can be obtained. Different strategies can be employed for obtaining the parameters of the above vibrational exciton Hamiltonian. First and most commonly, vibrational maps can be used, which provide an empirical parametrization of the local-mode frequencies ωi , the harmonic coupling constants J ij , and the local-mode transition dipoles μi as functions of the molecular structure and the electrostatic environment of the local oscillators. This is commonly combined with a fixed value for the local-mode anharmonic shift ∆.