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).
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 11, 2016
- Source ID
- 10.1063/1.4964391
Entities
People
- Andrew Horsfield
- Anne Ay Guilbert
- Max Boleininger
Organizations
- Air Force Office of Scientific Research
- Engineering and Physical Sciences Research Council
- Imperial College London
- Thomas Young Centre