First-principles studies on structural properties of β-cristobalite

The structure of β-cristobalite has been studied though a first-principles total-energy minimization in the local-density approximation using a Car–Parrinello-type algorithm combined with the Vanderbilt ultrasoft pseudopotential scheme. It was found that the hypothetical ordered structure proposed by Wright and Leadbetter is favored and the resulting structural parameters agree very well with experiment. Also, correlated relaxation of Si and O atoms toward α-cristobalite positions in the vicinity of domain boundaries is indicated.