We have calculated the energies of formation for various defects in a two-dimensional electron lattice. Included are vacancies and interstitials, dislocation pairs, and grain boundaries. From the results, we have extracted the dislocation core energy, and an approximate formula for the grain boundary energy as a function of angle. We discuss some possible implications for melting, and for dynamic processes such as electron diffusion and dislocation migration.

• Received 27 July 1979

DOI:https://doi.org/10.1103/PhysRevB.20.4692