Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electronic properties of DNA: structural and chemical influence on the
  quest for high conductance and charge transfer   Motivated by the wide ranging experimental results on the conductivity of
DNA, we have investigated extraordinary configurations and chemical
environments in which DNA might become a true molecular wire, perticularly from
enhanced electronic overlaps or from small activation energies. In particular,
we examine A- vs B-DNA, the ribbon-like structures proposed to arise from
molecular stretching, the potential role of counterions in hole doping the DNA
orbitals, the possibility of backbone conduction, and the effects of water. We
find that small activation gaps observed in conductivity experiments may arise
in the presence of water and counter ions. We further discuss the role of
harmonic vibration and twisting motion on electron tight binding matrix
elements using ab initio density functional theory and model Koster-Slater
theory calculations. We find that partial cancellation between pp-sigma and
pp-pi interaction of Pz orbitals on adjacent base pairs, along with destructive
interference of phase factors are needed to explain the weak conductance of
A-DNA. Our results lead also to a physical interpretation of the angular
dependence of inter-base pair tight binding matrix elements. Furthermore, we
estimate Franck-Condon factors, reorganization energies and nuclear frequencies
essential for charge transfer rates, and find our estimated hole transfer rates
between base pairs to be in excellent agreement with recent picosecond dynamics
data.

21
The categories of this paper are: adap-org
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
28
The categories of this paper are: alg-geom
36
The categories of this paper are: cmp-lg
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
23
The categories of this paper are: solv-int
8
The categories of this paper are: hep-ex
6
The categories of this paper are: astro-ph
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph