Stable and metastable structures of tin (IV) oxide at high pressure.

We have analysed SnO2 with a combination of synchrotron X-ray diffraction and X-ray absorption spectroscopy across a pressure range of 0→82.9 GPa with thermal annealing by a CO2 laser allowing access to all of the known high-density polymorphs of SnO2 , and here report their crystallographic information. The metastability of the post-rutile α - PbO2 and PdF2 structures in SnO2 are investigated by experiment and PW-DFT simulations, revealing a complex energetic landscape and suggesting a significant dependence of the observed phases on the pressure–temperature pathway taken in experiment. This article is part of the theme issue 'Exploring the length scales, timescales and chemistry of challenging materials (Part 1)'. [ABSTRACT FROM AUTHOR]