Stable one-component quasicrystals

The lowest-energy structures associated with a commonly used effective metallic pair potential are found for a wide range of values of the three parameters required by the potential. The structures tested include most of the lattices favored by the elements, the Bravais lattices with variable c/a and b/a ratios, and a number of candidate three-dimensional one-component quasicrystal structures. One of the quasicrystals is the stable structure for a region of parameter space close to the virtual-crystal parameters appropriate to the observed simple-metal quasicrystals. Energies are also evaluated for some crystalline approximants to the quasicrystals, and these structures are found to be lower in energy than the quasicrystal only for a small portion of the region of quasicrystal stability, although it is still possible that sufficiently high-order approximants are lower in energy over the entire region.