The crystal growth was carried out at LSPM-CNRS in a specially designed high-temperature cell of a toroid-type high-pressure apparatus equipped with direct-current heating system. Details of pressure and temperature calibration have been described earlier . The high-pressure cell was filled with ZnO microcrystalline powder (325 mesh, 99.9995% Alfa Aesar) mixed with one of the following dopants: Sb 2 O 3 (99.999%, Sigma-Aldrich); Sb (99,999%, Sigma-Aldrich); Zn (99.999%, Sigma-Aldrich) + Sb; As (99,999%, Sigma-Aldrich); Zn + As; P (99.999%, Sigma-Aldrich); Zn + P. Zn + X dopants were taken in 3:2 atomic ratio as for Zn 3 X 2 stoichiometric compounds to introduce the group-V elements in X -3 state. The powders were thoroughly grinded and then pressurized into a disk of 3.5 mm in diameter and 3 mm in height that was then gradually compressed up to 4.0 GPa and heated to 1700-1900 K with an average heating rate of 500 K/min.