  Ab initio modeling of molecular electronics is nowadays routinely performed
by combining the Density Functional Theory (DFT) and Nonequilibrium Green
function (NEGF) techniques. This method has its roots in the current formula
given by Meir and Wingreen, and we discuss some applications and accompanying
pitfalls and restrictions of this approach. Quite recently papers have begun to
appear where inelastic effects are considered, and we illustrate these new
developments by describing our own work on transport in atomic gold wires.
