First-principles calculations of elasticity and thermodynamic properties of LaNi5 crystal under pressure

This paper investigates the equilibrium lattice parameters, heatcapacity, thermal expansion coefficient, bulk modulus and itspressure derivative of LaNi₅ crystal by using thefirst-principles plane-wave pseudopotential method in the GGA-PBEgeneralized gradient approximation as well as the quasi-harmonicDebye model. The dependences of bulk modulus on temperature and onpressure are investigated. For the first time it analyses therelationships between bulk modulus B and temperature T up to1000K, the relationship between bulk modulus B and pressure atdifferent temperatures are worked out. The pressure dependences ofheat capacity C_v and thermal expansion α at varioustemperatures are also analysed. Finally, the Debye temperatures ofLaNi₅ at different pressures are successfully obtained. Thecalculated results are in excellent agreement with the experimentaldata.