We examine the effects of self-repulsion on the predictions of charge distribution in biased molecular junctions by the local density functional theory methods. This is done using a functional with explicit long-range exchange term effects [R. Baer, D. Neuhauser, Phys. Rev. Lett. 94 (2005) 043002]. We discuss in detail the new density functional, pointing out some of the remaining difficulties in the theory. We find that in weakly coupled junctions (the typical molecular electronics case) local-density functionals fail to describe correctly the charge distribution in the intermediate bias regime.
Bibliographical noteFunding Information:
We gratefully thank Prof. Paola Gori-Giorgi for interesting discussions and for supplying us with the computer routines for generating the pair correlation function of the HEG. We are grateful to the PRF, the NSF and the US-Israel Binational Science foundation for their support.
- Density functional theory
- Electron correlation
- Molecular electronics