Modeling proton transfer and polarons in a molecular crystal diamino-dinitroethylene

We applied embedded cluster and periodic methods to modeling the intramolecular and intermolecular hydrogen transfer and electron and hole trapping in a crystalline 1,1-diamino-2,2-dinitroethylene (DADNE) by means of density-functional theory and B3LYP functional. We predict self-trapping of both electrons and holes to occur and be accompanied by a strong lattice distortion in perfect DADNE crystals. The results also demonstrate that a combination of periodic and embedded-cluster techniques serve as a powerful simulation tool for revealing intricate details of the proton transfer in molecular crystals.