Electron transport in open systems from finite-size calculations: Examination of the principal layer method applied to linear gold chains
Abstract
We describe the occurrence of computational artifacts when the principal layer method is used in combination with the cluster approximation for the calculation of electronic transport properties of nanostructures. For a one-dimensional gold chain, we observe an unphysical band in the band structure. The artificial band persists for large principal layers and for large buffer sizes. We demonstrate that the assumption of equality between Hamiltonian elements of neighboring layers is no longer valid and that a discontinuity is introduced in the potential at the layer transition. The effect depends on the basis set. When periodic boundary conditions are imposed and the k-space sampling is converged, the discontinuity disappears and the principal layer method can be correctly applied by using a linear combination of atomic orbitals as basis set.
- Publication:
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Journal of Chemical Physics
- Pub Date:
- April 2008
- DOI:
- Bibcode:
- 2008JChPh.128o4713B
- Keywords:
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- 73.22.-f;
- 73.63.Bd;
- 71.15.Mb;
- 71.15.Ap;
- Electronic structure of nanoscale materials: clusters nanoparticles nanotubes and nanocrystals;
- Nanocrystalline materials;
- Density functional theory local density approximation gradient and other corrections;
- Basis sets and related methodology