ANALYSIS OF THE OPTICAL-SPECTRA OF AROMATIC-ALKANE CLUSTERS

Classical molecular dynamics simulations are applied to isolated tetra cene/(n-heptane)(n) clusters (n = 1-12). The spectroscopic shift of th e aromatic molecule is calculated via evaluation of the dispersion ter ms in the perturbation expansion of the intermolecular interactions, u sing a multipole expansion of the interaction Hamiltonian. Stable stru ctures, their energies and spectral shifts, optical lineshapes and vib rational modes are compared with two-color photo-ionisation spectra of such clusters in a molecular beam [Ben-Horin et al. Chem. Phys. Lett. 177, 153 (1991)]. Calculated shifts are in error by under 10% on aver age, enabling identification of most features of the experimental spec tra. (C) 1997 American Institute of Physics. [S0021-9606(97)51242-6].