Geometry and Conductance of Al Wires Suspended between Semi-Infinite Crystalline Electrodes

We present a first-principles study of a coherent relationship between the optimized geometry and conductance of a three-aluminum-atom wire during its elongation process. Our simulation employs the most definite model including semi-infinite crystalline electrodes using the overbridging boundary-matching method [Phys. Rev. B {\bf 67}, 195315 (2003)] extended to incorporate nonlocal pseudopotentials. The results that the conductance of the wire is $\sim$ 1 G$_0$ and the conductance trace as a function of electrode spacing shows a convex downward curve before breaking are in agreement with experimental data.