Green's function formalism coupled with Gaussian broadening of discrete states for quantum transport: Application to atomic and molecular wires

A Green's function formalism incorporating broadened density of states (DOS) is proposed for the calculation of electrical conductance. This approach combined with the density functional theory was applied to the electrical transmission of gold atomic wires and molecular wires. The width parameter was determined to reproduce the quantum unit of conductance in gold atomic wires. It was found that the Green's function formalism for quantum transport provides a useful strategy in the calculation of conductance.