Many-body potentials for semiconductors

  Semiconductors are even more challenging than metals. Take for instance silicon, and consider that

• the most stable phase in the absence of pressure has the diamond structure: very open, with a coordination number of only 4;
• when a pressure is applied, new structures with increasing coordinations appear in sequence ($\beta$-tin, simple cubic, fcc), indicating that they are not so far in energy;
• the liquid is a metal, and is more dense than the solid (anomalous).

These features alone guarantee that constructing a potential for Si is not a trivial task. Nevertheless, due to its technological importance, many groups have challenged themselves in this territory, with various degrees of success.