The calculation of the structural, mechanical and thermodynamic properties of the alkali hydrides XH (X = K, Rb and Cs) in rock-salt (RS), cesium chloride (CsCl), zinc-blende (ZB) and wurtzite (WZ) phases are done by using the full-potential linearized augmented plane wave (FP-LAPW) method within the frame work of the density functional theory (DFT) as implemented in the WIEN2K code. The Perdew–Burke–Ernzerhof generalized gradient approximation (PBE-GGA) was used for the exchange-correlation potential. The elastic constants and their related properties, as well as the thermodynamic properties, were obtained by using the IRelast package. The calculated elastic constants for the alkali hydrides, with the four structures RS, CsCl, ZB and WZ, at ambient pressure are mechanically stable. The elastic constants and their related properties in the RS structure are changeable with increasing pressure. Elastic constants, bulk modulus, shear modulus (stiffness) and Debye temperatures of these compounds are decreased as going from K to Cs in the periodic table. These compounds in the RS structure are mechanically stronger at ambient conditions. © 2018 The Physical Society of the Republic of China (Taiwan)q

Title

Chinese Journal of Physics

Publisher

Physical Society of the Republic of China

Publisher Country

China

Indexing

Thomson Reuters

Impact Factor

3.31

Publication Type

Prtinted only

Volume

56

Year

2018

Pages

830-843