2022/12/22 by Donaher, Shane, Agarwala, Puja, Milner, Scott T.
#Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)
paper · doi:10.48550/arxiv.2212.11831
The hopping matrix element t quantifies the quantum-mechanical coupling between frontier orbitals on a pair of nearby molecules. Convenient and generally applicable methods to determine t from DFT calculations are lacking; t can be obtained from coupling-induced energy splittings only if the interacting molecules are identical and symmetrically placed. We present a simple approach to determine t from DFT results that relies on measuring hybridization, projecting hybridized pair orbitals onto constituent frontier orbitals of the interacting molecules, using spatially discretized wavefunctions (``cube files'') rather than analytical representations. We demonstrate the method by exploring how t depends on the identity and relative placement of typical moieties found in semiconducting polymers.