Anomalous behavior of rutile GeO2 facets: A computational study

Due to its wide-ranging role in technologies such as electronic device manufacturing, strong attention has been devoted to GeO2. Although low-index facets of α-quartz polymorph of this mineral have been scrutinized in extenso, their rutile counterparts have been subject to oversight. We addressed this gap through a periodic first-principles approach. A multitude of DFT-based methods were exploited to examine the (110), (100), (101) and (001) sides of rutile GeO2. Unexpectedly, the (110) and (100) orientations turned out to be the most energetically preferred cuts, based on the method whereby they were simulated. On average, the stability sequence of the investigated planes was found as (110) > (100) > (101) > (001).