  We present the numerical tool DECaNT (Diffusion of Excitons in Carbon
NanoTubes) that simulates exciton transport in thin films of carbon nanotubes.
Through a mesh of nanotubes generated using the Bullet Physics C++ library,
excitons move according to an ensemble Monte Carlo algorithm, with the
scattering rates that account for tube chirality, orientation, and distance. We
calculate the diffusion tensor from the position--position correlation
functions and analyze its anisotropy and dependence on the film composition,
morphology, and defect density.
