Long range interactions on wires: a reciprocal space based formalism.

Abstract

There are many atomic scale systems in materials, chemistry, and biology that can be effectively modeled as finite in two of the physical spatial dimensions and periodically replicated in the third including nanoscale metallic and semiconducting wires, carbon nanotubes, and DNA. However, it is difficult to design techniques to treat long range forces in these systems without truncation or recourse to slowly convergent supercells or computationally inefficient Poisson solvers. In this paper, a rigorous reciprocal space based formalism which permits long range forces on wires to be evaluated simply and easily via a small modification of existing methods for three dimensional periodicity is derived. The formalism is applied to determine long range interactions both between point particles using an Ewald-like approach and the continuous charge distributions that appear in electronic structure calculations. In this way, both empirical force field calculations and, for example, plane-wave based density functional theory computations on wires can be performed easily. The methodology is tested on model and realistic systems including a lithium doped carbon nanotube.