Time-dependent density functional theory with ultrasoft pseudopotentials: Real-time electron propagation across a molecular junction
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A practical computational scheme based on time-dependent density functional theory (TDDFT) and ultrasoft pseudopotentials (USPP) is developed to study electron dynamics in real time. A modified Crank-Nicolson time-stepping algorithm is adopted, under plane-wave basis. The scheme is validated by calculating the optical absorption spectra for a sodium dimer and a benzene molecule. As an application of this USPP-TDDFT formalism, we compute the time evolution of a test electron packet at the Fermi energy of the left metallic lead crossing a benzene-(1,4)-dithiolate junction. A transmission probability of 5-7%, corresponding to a conductance of 4.0-5.6 S, is obtained. These results are consistent with complex band structure estimates and Green's function calculation results at small bias voltages. 2006 The American Physical Society.
author list (cited authors)
Qian, X., Li, J. u., Lin, X. i., & Yip, S.