title: Gaussian polarizable-ion tight binding.
abstract: To interpret ultrafast dynamics experiments on large molecules, computer simulation is required due to the complex response to the laser field. We present a method capable of efficiently computing the static electronic response of large systems to external electric fields. This is achieved by extending the density-functional tight binding method to include larger basis sets and by multipole expansion of the charge density into electrostatically interacting Gaussian distributions. Polarizabilities for a range of hydrocarbon molecules are computed for a multipole expansion up to quadrupole order, giving excellent agreement with experimental values, with average errors similar to those from density functional theory, but at a small fraction of the cost. We apply the model in conjunction with the polarizable-point-dipoles model to estimate the internal fields in amorphous poly(3-hexylthiophene-2,5-diyl).
authors: Department of Physics and Thomas Young Centre, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
authors: Max
authors: M
authors: Boleininger
authors: Department of Physics and Thomas Young Centre, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
authors: Anne Ay
authors: AA
authors: Guilbert
authors: Department of Materials and Thomas Young Centre, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
authors: Andrew P
authors: AP
authors: Horsfield