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Ab initio calculations are performed to investigate the structural stability, electronic structure and mechanical properties of BeAlH5 for monoclinic crystal structures with two different types of space group namely P21 and C2/c. Among the considered structures monoclinic (P21) phase is found to be the most stable at ambient condition. The structural phase transition from monoclinic (P21) to monoclinic (C2/c) phase is observed in BeAlH5. The electronic structure reveals that this compound is insulator. The calculated elastic constants indicate that this material is mechanically stable at ambient condition. [ABSTRACT FROM AUTHOR]

Ab initio calculations are performed to investigate the structural stability, electronic structure and mechanical properties of ABeH3 (A = Li, Na) for three different crystal structures, namely orthorhombic (Pnma), monoclinic (P21/c) and triclinic (P-1) phase. Among the considered structures monoclinic (P21/c) phase is found to be the most stable one for all the three hydrides at ambient condition. The electronic structure reveals that these materials are wide band gap semiconductors. The calculated elastic constants indicate that these materials are mechanically stable at ambient condition. [ABSTRACT FROM AUTHOR]

The electronic, structural and mechanical properties of ZrH and ZrH2 are investigated by means of first principles calculation based on density functional theory as implemented in VASP code with generalized gradient approximation. The calculated ground state properties are in good agreement with previous experimental and other theoretical results. Among the six crystallographic structures considered for ZrH, ZB phase is found to be the most stable phase, whereas ZrH2 is energetically stable in tetragonal structure at ambient condition. A structural phase transition from ZB→NaCl at a pressure 10 GPa is predicted for ZrH. [ABSTRACT FROM AUTHOR]

The structural, electronic and elastic properties of two alkali metal nitrides (MN: M= Rb, Cs) are investigated by the first principles calculations based on density functional theory using the Vienna ab-initio simulation package. At ambient pressure the two nitrides are stable in ferromagnetic state with CsCl structure. The calculated lattice parameters are in good agreement with the available results. The electronic structure reveals that these materials are half metallic in nature. A pressure-induced structural phase transition from CsCl to ZB phase is observed in RbN and CsN. [ABSTRACT FROM AUTHOR]

The structural and elastic properties of Hafnium dihydride (HfH2) are investigated by first principles calculation based on density functional theory using Vienna ab-initio simulation package (VASP). The calculated lattice parameters are in good agreement with the available results. A pressure induced structural phase transition from CaF2 to FeS2 phase is observed in HfH2 at 10.75 GPa. The calculated elastic constants indicate that this hydride is mechanically stable at ambient condition. [ABSTRACT FROM AUTHOR]

First principles calculation were performed using Tight-binding LMTO method with Local density approximation (LDA) and Atomic sphere approximation (ASA) to understand the electronic properties of CrH. A pressure induced structural phase transition from cubic to hexagonal structure of CrH is predicted. The stability of CrM2H is analyzed. [ABSTRACT FROM AUTHOR]

First principles calculation were performed using Tight-binding LMTO method with Local density approximation (LDA) and Atomic sphere approximation (ASA) to understand the electronic and magnetic properties of FeH and CoH. Our results indicate that both FeH and CoH is ferromagnetic at normal pressure and a pressure induced magnetic phase transition from ferromagnetic to nonmagnetic phase at high pressure is predicted. At normal pressure, the estimated magnetic moments are 4.99 (μB/FeH) and 1.72 (μB/CoH). It is in agreement with the experimental value. [ABSTRACT FROM AUTHOR]

First principles calculation were performed using ab-initio calculations to understand the electronic properties of transition metal trihydrides. The equilibrium geometries, the total DOS are obtained under various pressures. The most stable structure of the trihydrides is NaCl like structure. We estimated the average electron-phonon coupling constant, electron electron interaction parameter and superconducting Transition Temperature (Tc). Our results indicate that high superconductivity is observed in YH3 at a pressure of 40K. and is in agreement with the experimental value. [ABSTRACT FROM AUTHOR]

Ab initio calculations are performed to investigate the structural stability, electronic structure and mechanical properties of BeAlH5 for monoclinic crystal structures with two different types of space group namely P21 and C2/c. Among the considered structures monoclinic (P21) phase is found to be the most stable at ambient condition. The structural phase transition from monoclinic (P21) to monoclinic (C2/c) phase is observed in BeAlH5. The electronic structure reveals that this compound is insulator. The calculated elastic constants indicate that this material is mechanically stable at ambient condition. [ABSTRACT FROM AUTHOR]