DFT calculations of deuterium quadrupolar tensor in crystal anthracene

A DFT calculation of deuterium nuclear quadru- pole tensors of crystal anthracene is presented. After a care- ful analysis of the DFT functionals and of the basis sets, the B3LYP/6-311+G(d,3p2d) level has been identified as the best compromise between accuracy and computational cost. To account for the crystal environment, three models are proposed: one represented by a cluster of five anthracene arranged as in the crystal, the other formed by an anthra- cene embedded in a dielectric continuum having the dielec- tric permittivity of the crystal, and the last represented by an embedded dimer of anthracene. It is shown that the pure continuum model (here represented by the Integral Equation Formalism version of the Polarizable Continuum Model) al- ready accounts for a large part of the crystal effects and that the embedded dimer almost entirely recover all the details of the explicit 5-anthracene cluster.