Atomistic multiscale simulation of the structure and properties of an amorphous OXD-7 layer

The structure and properties of an amorphous 1,3-bis(2-(4-tert-butylphenyl)-1,3,4-oxadiazol-5-yl)benzene (OXD-7) layer are investigated by atomistic multiscale simulation combining quantum chemical (DFT, TDDFT) and molecular dynamics (MD, Amber force field) calculations. Three stable OXD-7 conformers are found on its ground-state DFT potential energy surface. The force-field parameters of torsion angles lacking in the Amber force field are determined by fitting to the results of MP2 calculations for a model oxadiazole derivative. The OXD-7 absorption band shape and HOMO and LUMO energy distributions in an amorphous film are found by TDDFT/DFT calculations for sample points obtained by MD calculations.