We investigate the application of a previously considered nonlinear wavepacket interferometry scheme to molecules with a single stable conformation in the electronic ground state. It is shown that interference experiments with pairs of phase-locked ultrashort pulse-pairs can be used to determine the complex overlaps of a nonstationary nuclear wavefunction evolving in an excited electronic state with a collection of compact displaced wavepackets moving in specified ways in the ground-state potential. (C) 2000 American Institute of Physics. [S0021-9606(00)00145-8].