Paz SA, Zoloff Michoff ME, Negre CFA, Olmos-Asar JA, Mariscal MM, Sánchez CG, Leiva EPM. Configurational Behavior and Conductance of Alkanedithiol Molecular Wires from Accelerated Dynamics Simulations.
J Chem Theory Comput 2012;
8:4539-45. [PMID:
26605613 DOI:
10.1021/ct3007327]
[Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An accelerated dynamics scheme is employed to sample the configurational space of a system consisting of an alkanedithiol molecule confined to the gap between a metal tip and a perfect metal surface. With this information and by means of nonequilibrium green functions techniques (NEGF), conductance calculations are performed. The present results show that even for this system, which is one of the most simple conceivable because of the perfectness of the surface, a complex behavior appears due to the occurrence of an unexpected tip-molecule-surface arrangement, where the insertion of one of the molecular ends into the tip-surface gap generates configurations with strongly enhanced conductance. Estimates are also made for the time required to generate the molecular junction, indicating that it should depend on the tip-surface distance, thus opening the way to new experiments in this direction.
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