Crystal structure and the equation of state of thorium monophosphide for pressures up to 50 GPa

High-pressure X-ray diffraction studies have been performed on ThP using synchrotron radiation and a diamond-anvil cell. The bulk modulus B₀ and its pressure derivative B'₀ have been determined (B₀ = 137 GPa; B'₀ = 5.1). A phase transition from the NaCl structure to the CsCl structure was observed at about 30 GPa.