Theoretical determination of anisotropic thermal conductivity for crystalline 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)

Bond stretching and three-center angle bending potentials have been developed to extend an existing rigid-bond 1,3,5-triamino-2,4,6-trinitrobenzene molecular dynamics force field [D. Bedrov, O. Borodin, G. D. Smith, T. D. Sewell, D. M. Dattelbaum, and L. L. Stevens, J. Chem. Phys. 131, 224703 (2009)] for simulations requiring fully flexible molecules. The potentials were fit to experimental vibrational spectra and electronic structure predictions of vibrational normal modes using a combination of zero kelvin eigenmode analysis for the isolated molecule and power spectra for the isolated molecule and crystal. A reverse non-equilibrium molecular dynamics method [F. Muller-Plathe, J. Chem. Phys. 106, 6082 (1997)] was used to obtain the room temperature, atmospheric pressure thermal conductivity along three directions in a well-defined, non-orthogonal basis. The thermal conductivity was found to be significantly anisotropic with values 1.13 +/- 0.07, 1.07 +/- 0.07, and 0.65 +/- 0.03 W m(-1) K-1 for directions nominally parallel to the a, b, and c lattice vectors, respectively. (C) 2013 AIP Publishing LLC.