The crystallographic structures for PbWO4-I (raspite), PbWO 4-II (scheelite) and PbWO4-III (BaWO4-II like) have been studied using the Vienna ab initio simulation package (VASP) code within the local density approximation (LDA). PbWO4-I and PbWO 4-II were experimentally observed to coexist under normal conditions and a transformation to PbWO4-III transition was reported to take place around 25kbar at 600°C. In our calculation, the raspite structure was computed to be more stable to the scheelite structure at ambient pressure with an energy difference of 25 meV/atom. At 18 kbar, we calculated a transformation from the raspite to the PbWO4-III structure, which is in reasonable agreement with the experiment.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics