,Structural, electronic, elastic, and thermal properties of CaNiH3 perovskite obtained from first-pr

• 作 者: S Benlamari H Bendjeddou R Boulechfar S Amara Korba H Meradji R Ahmed S Ghemid R Khenata S Bin Omran
• 机 构: Laboratoire LPR, Département de Physique, Faculté des Sciences, Université Badji Mokhtar, Annaba, Al
• 出 处: 中国物理B（英文版）
• 发表日期: 2018年3期
• 关键词: perovskite-type hydrides elastic constants hydrogen storage materials

A theoretical study of the structural,elastic,electronic,mechanical,and thermal properties of the perovskite-type hydride CaNiH3 is presented.This study is carried out via first-principles full potential (FP) linearized augmented plane wave plus local orbital (LAPW+lo) method designed within the density functional theory (DFT).To treat the exchangecorrelation energy/potential for the total energy calculations,the local density approximation (LDA) of Perdew-Wang (PW) and the generalized gradient approximation (GGA) of Perdew-Burke-Emzerhof (PBE) are used.The three independent elastic constants (Cll,C12,and C44) are calculated from the direct computation of the stresses generated by small strains.Besides,we report the variation of the elastic constants as a function of pressure as well.From the calculated elastic constants,the mechanical character of CaNiH3 is predicted.Pertaining to the thermal properties,the Debye temperature is estimated from the average sound velocity.To further comprehend this compound,the quasi-harmonic Debye model is used to analyze the thermal properties.From the calculations,we find that the obtained results of the lattice constant (a0),bulk modulus (B0),and its pressure derivative (B0’) are in good agreement with the available theoretical as well as experimental results.Similarly,the obtained electronic band structure demonstrates the metallic character of this perovskite-type hydride.