Lattice dynamical and thermodynamical properties of ReB2, RuB2, and OsB2 compounds in the ReB2 structure

WOS: 000309817400057Structural and lattice dynamical properties of ReB2, RuB2, and OsB2 in the ReB2 structure are studied in the framework of density functional theory within the generalized gradient approximation. The present results show that these compounds are dynamically stable for the considered structure. The temperature-dependent behaviors of thermodynamical properties such as internal energy, free energy, entropy, and heat capacity are also presented. The obtained results are in good agreement with the available experimental and theoretical data

Lattice dynamical properties of ScB2, TiB2, and VB2 compounds

WOS: 000270690000027We have investigated the structural and lattice dynamical properties of XB2(X = Sc, V, Ti) by using first-principles total energy calculations. Specifically, the lattice parameters (a, c) of the stable phase, the bond lengths of X-B and B-B atoms, phonon dispersion curves and the corresponding density of states, and some thermodynamical quantities such as internal energy, entropy, heat capacity, and their temperature-dependent behaviours, are presented. The obtained results for structural parameters are in good agreement with the available experimental and other theoretical studies.Gazi University Research-Project Unit [05/2008-42]This work is supported by Gazi University Research-Project Unit under Project No: 05/2008-42

The structural, thermodynamical, elastic, and vibrational properties of LaBi

WOS: 000258317600005In this study, we have studied the structural, elastic, electronic, thermodynamical, and vibrational properties of LaBi by performing ab initio calculations within the local-density approximation (LDA). In particular, the lattice constant, bulk modulus, cohesive energy, phase transition pressure (P-t) from the NaCl (B1) to the CsCl (B2) structure, second-order elastic constants (C-ij), electronic band structures, and lattice dynamical properties were calculated and compared with the available experimental and other theoretical values. In order to obtain further information, we have also predicted Young's modulus (E), Poisson's ratio (v), the anisotropy factor (A), sound velocities, Debye temperature (theta(D)), and their pressure-dependent behaviour in the B1 phase. In addition, we have estimated the temperature-dependent behaviour of some thermodynamical properties, such as entropy and heat capacity from the lattice dynamical data

Ab initio study on hypothetical silver nitride

We perform the ab initio calculations based on norm-conserving pseudopotentials and density functional theory to investigate the structural, elastic, and thermodynamical properties for silver nitride (AgN) compound that is a member of the 4d transition metal group and has not been synthesized yet. The obtained results are compared with the other available theoretical data, and the agreement is, generally, quite good. We also present the pressure-dependent behaviour of some mechanical and thermodynamical properties for the same compounds. © 2008 Chinese Physical Society and IOP Publishing Ltd