The ONIOM(B3LYP/6-31G(d,p):PM3) procedure was used for optimization of terrylene molecule embedded into a naphthalene crystal, which crystallographic lattice was described by the PM3 method. Experimentally observed appearance of the new (absent for isolated molecule) vibronic line in fluorescence excitation spectrum of terrylene in the crystal was attributed to lowering of the molecule symmetry from D-2h to C-i. Further refinement of the molecule coordinates was proposed in order to achieve the experimentally observed intensity distribution in the fluorescence excitation spectrum. (C) 2017 Elsevier B.V. All rights reserved.