Fragment transition density method to calculate electronic coupling for excitation energy transfer.

摘要: A general approach, the Fragment Transition Density (FTD) scheme, is introduced to estimate electronic coupling for excitation energy transfer in a molecular system. Within this method, energies and transition densities of system are used derive matrix element. The scheme allows one treat systems where exciton donor acceptor close together their exchange interaction orbital overlap significant. FTD method can be applied combination with any quantum mechanical approach excited states nature including single-, double-, higher excitations. Using we excitonic couplings several computed CIS, TD DFT MS-CASPT2 methods. In particular, it shown that estimated values DNA π-stacks strongly affected by short-range adjacent nucleobases.