Two-dimensional correlation spectroscopies of localized vibrations

One- and two-dimensional vibrational response functions which may be used i n the simulations of molecular fifth-order Raman and second-order infrared techniques are calculated for a set of interacting localized anharmonic vib rations. Employing a vibrational Frenkel exciton model we have accounted fo r exciton-exciton scattering due to quartic anharmonicities as well as for the creation and annihilation of one vibrational quanta by cubic anharmonic ities. Closed expressions for the optical response are given in terms of th e one- and two-exciton Green functions, the exciton scattering matrix and t he exciton population Green function. (C) 2001 Elsevier Science B.V. All ri ghts reserved.