Speaker
Apply to be<br> consider for a student <br> award (Yes / No)?
No
Main supervisor (name and email)<br>and his / her institution
Prof. Daniel P. Joubert
Daniel.Joubert2@wits.ac.za
University of the Witwatersrand
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
Yes
Abstract content <br> (Max 300 words)
We present results of ab initio total energy calculations for the bulk structural phases of ZnO under high pressure. The study is based on density functional theory (DFT), using the projector augmented wave (PAW) potentials, and the Heyd-Scuseria-Ernzerhof (HSE06) screened hybrid density functional for electron exchange and correlation. Apart from the ambient pressure B4 (hexagonal wurtzite) structure, and the B3 (cubic zinc blende) structures, a tetragonal B10 (PbO-type) structure is predicted to be an intermediate phase (at about 273 GPa) between the high-pressure B1 (cubic rocksalt) and B2 (cubic CsCl) phases. It is shown that the HSE functional yields lattice constants and bulk moduli in better agreement with experiment than the widely used conventional exchange correlation functionals. Most importantly, HSE band structure calculations result in significantly improved semiconducting energy band gaps for ZnO over the widely used semilocal functionals, thus improving agreement with experiments.