Electronic properties of DNA by DFT calculations based on fragment molecular orbital method

Abstract

Fragment molecular orbital (FMO) method is one of the approximations for calculating electronic properties of huge molecules such as DNA and protein. The accuracy and computational cost of FMO calculations depend critically on the way of dividing a molecule into fragments. In this study, we investigated the electronic properties of four types of DNA models by using our developed density functional (DFT) method based on FMO. In the FMO-DFT calculations, we considered the two types of ways of division for fragmentation, i.e., divisions into DNA bases and base pairs. Through the comparison with the results by conventional DFT calculations, it was clarified that the FMO-DFT calculations with a base fragmentation as well as with a base-pair fragmentation have a comparable accuracy with that obtained by the conventional DFT method for the electronic properties of DNA.