Pressure-induced phase transitions, electronic, elastic and vibrational properties of zinc oxide under high pressure

In this work, the crystal structure of the ZnO was studied under high hydrostatic pressure using ab initio calculations. Pressure–volume relationships and structural transitions in ZnO were investigated using Siesta method. A first-order transition from the hexagonal wurtzite (B4) structure with space group P63mc\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ P6_{3} mc $$\end{document} to the cubic NaCl (B1) structure with space group Fm3¯m\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ Fm\bar{3}m $$\end{document} was successfully observed. A transition was also observed from Fm3¯m\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ Fm\bar{3}m $$\end{document} to another cubic CsCl (B2) structure with space group Pm3¯m\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ Pm\bar{3}m $$\end{document} for ZnO. These phase transitions which occur around 9 and 119.5 GPa were also analyzed from the total energy and enthalpy calculations. In addition, electronic, elastic and vibrational properties of ZnO were analyzed based on the high pressure.