  The thermal conductivity of double-stranded (ds) B-DNA was systematically
investigated using classical molecular dynamics (MD) simulations. The effect of
changing base-pairs on the thermal conductivity of dsDNA, needed investigation
at a molecular level. Hence, four sequences, viz. poly(A), poly(G), poly(CG)
and poly(AT) were initially analysed in this work. Firstly, length of these
sequences was varied from 4-40 base-pairs (bp) at 300 K and the respective
thermal conductivity ($\mathrm{\kappa}$) was computed. Secondly, the
temperature dependent thermal conductivities between 100 K and 400 K were
obtained in 50 K steps at 28 bp length. The M\"{u}ller-Plathe reverse
non-equilibrium molecular dynamics (RNEMD) was employed to set a thermal
gradient and obtain all thermal conductivities in this work. Moreover, mixed
sequences using AT and CG sequencces, namely $\mathrm{A(CG)_{n}T}$ (n=3-7),
$\mathrm{ACGC(AT)_{m}GCGT}$ (m=0-5) and $\mathrm{ACGC(AT)_{n}AGCGT}$ (n=1-4)
were investigated based on the hypothesis that these sequences could be better
thermoelectrics. 1-dimensional lattices are said to have diverging thermal
conductivities at longer lengths, which violate Fourier law. These follow power
law, where $\mathrm{\kappa \propto\ L^{\beta}}$. At longer lengths, the
exponent $\mathrm{\beta}$ need to satisfy the condition $\mathrm{\beta}>1/3$
for divergent thermal conductivity. We find no such significant Fourier law
violation through divergence of thermal conductivities at 80 bp lengths or 40
bp lengths. Also, in the case of second study, the presence of short (m$\le$2)
encapsulated AT sequences within CG sequences show an increasing trend. These
significant results are important for engineering DNA based thermal devices.
