ATOMIC AND ELECTRONIC-STRUCTURES OF RECONSTRUCTED SI(100) SURFACES

New structural models for 2×1 and 4×2 reconstructed (100) surfaces of Si determined from energy-minimization claculations are presented. The optimal 2×1 and 4×2 structures are found to correspond to asymmetric dimer geometries with partially ionic bonds between surface atoms, resulting in semiconducting surface electronic bands. The atomic and electronic structures for the 2×1 and 4×2 reconstructed surfaces are discussed. © 1979 The American Physical Society.