Proton dynamics in a tropolone crystal was studied by 2D quantization of nuclear motions using Born-Oppenheimer molecular dynamics. This study presents the characteristics of the conjugated system of O-H stretching vibrations in the tropolone crystal. The MD simulations elucidate the presence of a pseudo-cyclic dimer structure in the crystal phase. The results obtained herein were compared with the IR spectroscopic data for the tropolone crystal. The skeleton and butterfly motions of the seven carbon rings strongly influence the strength of the hydrogen bonds in the cyclic dimers and are extensively discussed in this paper. (C) 2018 Elsevier B.V. All rights reserved.