The construction of a reliable potential for GeO₂ from first principles

Abstract

The construction of a reliable potential for GeO₂ from first principles is described. The obtained potential, which includes dipole polarization effects, is able to reproduce all the studied properties (structural, dynamical and vibrational) to a high degree of precision with a single set of parameters. In particular, the infrared spectrum was obtained using the expression proposed for the dielectric function of polarizable ionic solutions reported by Weis et al. [J. Chem. Phys. 91, 5544 (1989)]. The agreement with the experimental spectrum is very good, with three main bands that are associated with tetrahedral modes of the GeO₂ network. Finally, we give a comparison with a simpler pair-additive potential.

Keywords:

• GeO₂
• molecular dynamics
• infrared spectrum
• polarization effects
• SiO₂

Acknowledgements

We thank Philip Salmon for providing his diffraction data. Calculations were carried out at the EaStCHEM computing facility (http://www.eastchem.ac.uk/rcf). DM thanks the EPSRC and the CMPC for PhD funding. This work was carried out under the HPC-EUROPA++ project (project number 211437) with the support of the European Community—Research Infrastructure Action of the FP7 ‘Coordination and support action’ Programme.