In search of new reconstructions of (001) α-quartz surface: A first principles study

Abstract

Using Born-Oppenheimer molecular dynamics (BOMD) simulations and "static" density functional theory (DFT) calculations, the stability of cleaved and reconstructed α-SiO2(001) surfaces was studied. We found reconstructions ("dense", 2 × 2 reoptimized "dense", and 3 × 3 reoptimized "dense") which minimize the surface energy. The analysis of the surface energies shows that the cleaved surface reconstructs to the 2 × 2 reoptimized "dense" surface having a surface energy around 10% smaller than the "dense" surface. The results suggest that the optimization of Si-Si and Si-O distances at top surface layers plays the key role in stabilizing the 2 × 2 "dense" surface over the well-known "dense" surface.