2003-2004 Colloquium Series

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NAU Physical Sciences (Bldg 19, Rm 233), Tuesday, 13 April 2004, 4:00 PM
(Refreshments at 3:45pm)

Dynamically Amorphous Character of Electronic States in DNA:
Does DNA make a good molecular wire?

James P. Lewis, Brigham Young University.

Abstract

In the literature, much theoretical work has been done in the area of trying to understand the electronic structure and electron (hole)-transfer properties of DNA. DNA is an ideal candidate in molecular electronics (as a molecular wire?) due to its 'built-in' one-dimentionality. One important avenue of investigation is the understanding of how the dynamics of the DNA strand might affect the electronic structure and hence the electron(hole)-transport. But, due to the size of the molecular system, quantum-based atomistic models for large DNA strands containing several base pairs have made very little contribution in this area. The first atomistic ab initio electronic-structure investigation of a large DNA strand (10 base pairs) was reported by J.P. Lewis et al. (1997). Prior to this work, only non-atomistic semi-empirical methods have been applied to DNA. We will discuss our more results where state-of-the-art molecular dynamics simulations, including an explicit representation of solvent and counterions and a proper treatment of the long-ranged electrostatic interactions, of duplex DNA were performed. Snapshots of the trajectory were coupled to calculations of the electronic structure to produce a 'time-dependent' picture of charge transfer in DNA.

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