Closed systems of equations of correlation functions of currents for heterogeneous DNA fragments and polarons

• Published in: Computational and theoretical chemistry 2017-06, Vol.1109, p.19-26
• Main Authors: Ponomarev, O.A., Shigaev, A.S., Galakhar, A.S., Lakhno, V.D.
• Format: Article
• Language: English
• Subjects: DNA fragment; Polaron; The Kubo formula
• ISSN: 2210-271X
• DOI: 10.1016/j.comptc.2017.03.035

[Display omitted] •A closed system of equations is obtained to identify conductivity control parameters for DNA fragments.•It is demonstrated that adjacent sites define the local conductivity of DNA in one-dimensional case.•The effect of polaron well on hole transfer in DNA is ascertained. A closed system of nonlinear differential equations is proposed for current correlation functions of the Kubo expression for conductivity. The chain of equations is closed by dropping the correlations of higher order. The approach allows estimating an error of the dropped correlations. A successive approximation technique can take account of the corrections and allow for subtle effects caused by DNA structure and identifies areas, where these corrections are significant. The local conductivity in one-dimensional case was shown to be defined by adjacent sites. Zone conductivity takes place for small electron-vibrational interactions. The conductivity decreases with temperature rise, but it may increase or decrease at low temperatures because of finiteness of polymer fragment. At low temperatures the zone conductivity persists for large electron-vibrational interactions, however the possibility of hopping appears, and hopping conductivity increases with temperature rise and becomes determinant at some temperature but starts decreasing with temperature rise at high temperatures.