The stability mechanism of cuboctahedral clusters in nonstoichiometric uranium dioxide is investigated by first-principles LSDA+U method. Calculations reveal that the structural stability is inherited from U6O12 molecular cluster whereas the energy gain through occupying its center with an additional oxygen makes the cluster win out by competition with point oxygen interstitials. Local displacement of the center oxygen along <111> direction also leads the cluster 8-folded degeneracy and increases relatively the concentration at finite temperatures. But totally, elevation of temperature, i.e., the effect of entropy, favors point interstitial over cuboctahedral clusters.
By first-principles LSDA+U calculations, we revealed that the current physical picture of defective uranium dioxide suggested solely by neutron diffraction analysis is unsatisfactory. An understanding based on quantum theory has been established as a thermodynamical competition among point defects and cuboctahedral cluster, which naturally interprets the puzzled origin of the asymmetric O' and O'' interstitials. It also gives a clear and consistent agreement with most available experimental data. Unfortunately, the observed high occupation of O'' site cannot be accounted for in this picture an…
Formation Gibbs free energy of point defects and oxygen clusters in uranium dioxide at high-pressure high-temperature conditions are calculated from first principles, using the LSDA+U approach for the electronic structure and the Debye model for the lattice vibrations. The phonon contribution on Frenkel pairs is found to be notable, whereas it is negligible for the Schottky defect. Hydrostatic compression changes the formation energies drastically, making defect concentrations depend more sensitively on pressure. Calculations show that, if no oxygen clusters are considered, uranium vacancy bec…
We study the electronic and structural properties of the low-temperature ordered phase of hydrogen-bonded molecular conductors, $κ$-D$_3$(Cat-EDT-TTF)$_2$ and its selenium-substituted analog $κ$-D$_3$(Cat-EDT-ST)$_2$, by means of first-principles density functional theory~(DFT) calculations. In these compounds, the charge ordering in the $π$-electron system is coupled with the ordering of the displacements in the deuteriums forming the hydrogen-bond, equally shared by two oxygens in the high-temperature phase. While the structural optimization within the standard DFT method based on the genera…
The stability of ($R$, Zr)(Fe, Co, Ti)$_{12}$ with a ThMn$_{12}$ structure is investigated using first-principles calculations. We consider energetic competition with multiple phases that have the Th$_2$Zn$_{17}$ structure and the unary phases of $R$, Zr, Fe, Co, and Ti simultaneously by constructing a quinary energy convex hull. From the analysis, we list the stable phases at zero temperature, and show possible stable and metastable ThMn$_{12}$ phases.
The properties of perfect screw dislocations have been investigated for several zinc-blende materials such as diamond, Si, $β$-SiC, Ge and GaAs, by performing first principles calculations. For almost all elements, a core configuration belonging to shuffle set planes is favored, in agreement with low temperature experiments. Only for diamond, a glide configuration has the lowest defect energy, thanks to an sp$^2$ hybridization in the core.
The structural stability and electronic states of GaSe monolayer with trigonal-antiprismatic (AP) structure, which is a recently discovered new polymorph, were studied by first-principles calculations. The AP phase GaSe monolayer was found stable, and the differences in energy and lattice constant were small when compared to those calculated for a GaSe monolayer with conventional trigonal-prismatic (P) structure which was found to be the ground state. Moreover, it was revealed that the relative stability of P phase and AP phase GaSe monolayers reverses under tensile strain. These calculation r…
We report an ab-initio study of the stability and electronic properties of transition metal silicides in order to study their potential for high temperature thermoelectric applications. We focus on the family M5Si3 (M = Ta, W) which is stable up to about 2000 °C. We first investigate the structural stability of the two compounds and then determine the thermopower of the equilibrium structure using the electronic density of states and Mott's law. We find that W5Si3 has a relatively large thermopower but probably not sufficient enough for thermoelectric applications.
We have applied a shell model potential developed by fitting first principle results to describe the behavior of the relaxor-ferroelectric PMN-xPT as function of concentration. The solid solution exhibits three regions with different characteristics according to Ti content in agreement with the experiments. At low Ti the polar and structural disorder dominates, and the symmetry is rhombohedral. The intermediate region is ferroelectric with easy rotation of the polarization direction, and the symmetry appears orthorhombic. Finally, in the high Ti content region, the solid solution adopts a ferr…
Recently synthesized NdFe12N has excellent magnetic properties, while it is thermodynamically unstable. Using first-principles method, we study the effect of substitutional 3d transition metal elements to the mother compound NdFe12. We find that Co has positive effect on the stability of the ThMn12 structure. In contrast with Ti substitution, Co substitution does not reduce the magnetization significantly. The crystal field parameter <r^{2}>A_{0}^{2} is nearly unchanged by Co substitution, and nitrogenation to NdFe11Co greatly enhances <r^{2}>A_{0}^{2}. This suggests that Co is a good candidat…
First-principles DFT levels of calculations have been carried out in order to study the structural stability and electronic properties of hydrogen passivated graphene (H-graphene) clusters. Two different shaped clusters, rectangular and circular, consisting of 6 to 160 carbon atoms and hydrogen termination at the zigzag boundary edges have been studied. The relative stability of rectangular shaped cluster consisting 96 C-atoms found to be 1.5% greater than that of circular shape cluster consisting same number of C-atoms. In comparing circular and rectangular cluster containing same number of C…
First-principles calculations through a FLAPW-GGA method for six possible polymorphs of ruthenium mononitride RuN with various atomic coordination numbers CNs: cubic zinc blende (ZB) and cooperite PtS-like structures with CNs = 4; cubic rock-salt (RS), hexagonal WC-like and NiAs-like structures with CNs = 6 and cubic CsCl-like structure with CN = 8 indicate that the most stable is ZB structure, which is much more preferable for RuN than the recently reported RS structure for synthesized RuN samples. The elastic and electronic properties of ZB-RuN were investigated and discussed in comparison w…
This paper reviews and summarizes the recent first-principles theoretical studies of the structural stability, electronic structure, optical and magnetic properties of nonmetal-doped TiO$_2$. The first section presents a comparison study of the structural stability for X-anion and X-cation doped TiO$_2$ (X=B, C, Si, Ge, N, P, As, Sb, S, Se, Te, F, Cl, Br, and I), which reveals that the sites of nonmetal dopants (i.e., at O sites or at Ti sites) in TiO$_2$ are determined by the growth condition of doped TiO$_2$ and the dopants' electronegativities. The next section reviews the electronic struct…
We investigate the structural stability and magnetic properties of cubic, tetragonal and hexagonal phases of Mn3Z (Z=Ga, Sn and Ge) Heusler compounds using first-principles density-functional theory. We propose that the cubic phase plays an important role as an intermediate state in the phase transition from the hexagonal to the tetragonal phases. Consequently, Mn3Ga and Mn3Ge behave differently from Mn3Sn, because the relative energies of the cubic and hexagonal phases are different. This result agrees with experimental observations from these three compounds. The weak ferromagnetism of the h…
The pressure-induced transition of vanadium from BCC to rhombohedral structures is unique and intriguing among transition metals. In this work, the stability of these phases is revisited by using density functional theory. At finite temperatures, a novel transition of rhombohedral phases back to BCC phase induced by thermal electrons is discovered. This reentrant transition is found not driven by phonons, instead it is the electronic entropy that stabilizes the latter phase, which is totally out of expectation. Parallel to this transition, we find a peculiar and strong increase of the shear mo…
We report ab initio investigations of hexagon-shaped, [111]/[0001] oriented III-V semiconductor nanowires with varying crystal structure, surface passivation, surface orientation, and diameter. Their stability is dominated by the free surface energies of the corresponding facets which differ only weakly from those of free surfaces. We observe a phase transition between local zinc-blende and wurtzite geometry versus preparation conditions of the surfaces, which is accompanied by a change in the facet orientation. The influence of the actual III-V compound remains small. The atomic relaxation of…
Elastic and structural properties of $β$-Ga$_2$O$_3$ and $α$-Ga$_2$O$_3$ are investigated from first principles. The full elastic tensors and elastic moduli of both phases at $0$ K are computed in the framework of semi-local density-functional theory. We determine mechanical instabilities of $β$-Ga$_2$O$_3$ by evaluating the full stiffness tensor under load for a range of hydrostatic pressure values. While a phase transition from the $β$ to $α$ phase is found to be energetically favored at $2.6$ GPa, we show that the $β$ phase is only mechanically unstable for much higher pressures ($>30$ GPa)…
In order to clarify thermodynamic stability of Mg-based long-period stacking ordered (LPSO) structure, we systematically study energetic preference for alloys on multiple stacking with different composition for random mixing of constituent elements, Mg, Y, and Zn based on special quasirandom structure (SQS). Through calculation of formation free energy of SQS, Mg-Y-Zn alloy exhibits phase separation into Mg- and Y-Zn rich phase, which is consistent with previous theoretical studies. Bulk modulus of SQSs for multiple compositions, stacking sequences, and atomic configuratons ranges around 35 GP…
High entropy alloys (HEAs) are multicomponent compounds whose high configurational entropy allows them to solidify into a single phase, with a simple crystal lattice structure. Some HEA's exhibit desirable properties, such as high specific strength, ductility, and corrosion resistance, while challenging the scientist to make confident predictions in the face of multiple competing phases. We demonstrate phase stability in the multicomponent alloy system of Cr-Mo-Nb-V, for which some of its binary subsystems are subject to phase separation and complex intermetallic-phase formation. Our first-pri…
Recent theoretical studies have predicted magnetic states for Ru and Os in the body centered tetragonal structure (bct) with c/a < 1. In this study, we present first principles calculations of the phonon dispersion for ferromagnetic Ru- and Os-bct along the epitaxial and uniaxial Bain paths, to evaluate their dynamical stability. The phonon dispersions were computed using the density function perturbation theory, including the gradient corrections to the exchange-correlation functional within the plane-waves ultrasoft-pseudopotential approximation. The phonon dispersion for the local minimum i…
We present an ab initio investigation of the interaction between methane, its dehydrogenated forms and the cerium oxide surface. In particular, the stoichiometric CeO2(111) surface and the one with oxygen vacancies are considered. We study the geometries, energetics and electronic structures of various configurations of these molecules adsorbed on the surface in vacuum, and we extend the analysis to realistic environmental conditions. A phase diagram of the adsorbate-surface system is constructed and relevant transition phases are analyzed in detail, showing the conditions where partial oxidat…
The elastic, thermodynamic, and optical properties of Mo_{2}TiAlC_{2} are investigated by first-principles calculations. Our results indicate that the a axis is stiffer than c axis within 0~100 GPa. Elastic constants calculations predict the large stability range of Mo_{2}TiAlC_{2} under pressure. Several important thermodynamic properties are discussed detailedly, including the Debye temperature, thermal expansion coefficient, and heat capacity etc. The bonding properties are studied from the elastic quantities and electronic properties. The electronic properties are investigated, including t…
Here, the first-principles predictions on the structural stability, magnetic behavior and electronic structure of B-site ordered double perovskite Nd$_{2}$FeCrO$_{6}$ have been reported. Initially, the ground state of the parent single perovskites NdCrO$_{3}$ and NdFeO$_{3}$ have been studied to determine the relevant Hubbard U parameter to investigate the properties of Nd2CrFeO6. The thermodynamic, mechanical, and dynamic stability analyses suggest the possibility of the synthesis of Nd$_{2}$FeCrO$_{6}$ double perovskite at ambient pressure. The compound shows ferrimagnetic (FiM) nature with …
Structural stability, electronic band structure, and optoelectronic properties of quaternary chalcogenide CuZn2MS4 (M =In and Ga) compounds via first principles
Using combination of Density Functional Theory and Monte Carlo simulation, we study the phase stability and electronic properties of two dimensional hexagonal composites of boron nitride and graphene, with a goal to uncover the role of the interface geometry formed between the two. Our study highlights that preferential creation of extended armchair interfaces may facilitate formation of solid solution of boron nitride and graphene within a certain temperature range. We further find that for band-gap engineering, armchair interfaces or patchy interfaces with mixed geometry are most suitable. E…
We employ a multiscale modeling approach to study the surface structure and composition of a Pd(100) model catalyst in reactive environments. Under gas phase conditions representative of technological CO oxidation (~1 atm, 300-600 K) we find the system on the verge of either stabilizing sub-nanometer thin oxide structures or CO adlayers at the surface. Under steady-state operation this suggests the presence or continuous formation and reduction of oxidic patches at the surface, which could be key to understand the observable catalytic function.
Alanates and boranates are studied intensively because of their potential use as hydrogen storage materials. In this paper we present a first-principles study of the electronic structure and the energetics of beryllium boranate, Be(BH4)2. From total energy calculations we show that - in contrast to the other boranates and alanates - hydrogen desorption directly to the elements is likely, and is at least competitive with desorption to the elemental hydride (BeH2). The formation enthalpy of Be(BH4)2 is only -0.12 eV/H2 (at T=0K). This low value can be rationalized by the participation of all ato…
The existence of two novel hybrid two-dimensional (2D) monolayers, 2D B3C2P3 and 2D B2C4P2, has been predicted based on the density functional theory calculations. It has been shown that these materials possess structural and thermodynamic stability. 2D B3C2P3 is a moderate band gap semiconductor, while 2D B2C4P2 is a zero band gap semiconductor. It has also been shown that 2D B3C2P3 has a highly tunable band gap under the effect of strain and substrate engineering. Moreover, 2D B3C2P3 produces low barriers for dissociation of water and hydrogen molecules on its surface, and shows fast recover…
The thermodynamical stability of ${\rm Al(BH_4)_3}$ has been investigated using first-principles calculations based on density functional theory. The heats of formation are obtained to be -132 and $-131 {\rm kJ/mol}$ without the zero-point energy corrections for $α$- and $β$-${\rm Al(BH_4)_3}$, respectively, which are made up of discrete molecular ${\rm Al(BH_4)_3}$ units. It is predicted correctly that the $α$ phase is more stable than the $β$ phase. The energy difference between the solid phases and the isolated molecule is only about 10 kJ/mol. An analysis of the electronic structure also s…
To understand the vibrational and configurational entropy effects for the stability of core-shell and solid-solution bimetallic nanoparticles, we theoretically investigated the excess energy of PdPt nanoparticles, adopting the (PdPt)201 model of ca. 2 nm by using the density functional method. The vibrational energy and entropy terms contributed to the total energy of both core-shell and solid-solution nanoparticles. The configurational entropy term was defined only for the solid-solution nanoparticles. Although the absolute values of vibrational energy and entropy terms were much larger than …
SrHfO3 is a potential dielectric material for metal-oxide-semiconductor (MOS) devices. SrHfO3/GaAs interface has attracted attention due to its unique properties. In this paper, the interface properties of (001) SrHfO3/GaAs are investigated by frst principles calculations based on density functional theory (DFT). Firstof all, the adsorption behavior of Sr, Hf and O on GaAs surface is investigated. O has lower adsorption energy on Ga surface than on As surface. Then, some possible (0 0 1) SrHfO3/GaAs confgurations are considered to analyze the interface spacing, stability, band offsets and char…
Based on first-principles electron structure calculations and employing the frozen-magnon approximation we study the exchange interactions in a series of transition-metal binary alloys crystallizing in the zinc-blende structure and calculate the Curie temperature within both the mean-field approximation (MFA) and random-phase approximation (RPA). We study two Cr compounds, CrAs and CrSe, and four Mn compounds: MnSi, MnGe, MnAs and MnC. MnC, MnSi and MnGe are isovalent to CrAs and MnAs is isoelectronic with CrSe. Ferromagnetism is particular stable for CrAs, MnSi and MnGe: All three compounds s…
Experimental data on the structure of ferroelectric oxide Bismuth Titanate suggests two different kinds of structures i.e. orthorhombic and monoclinic. We have performed density functional theory (DFT) based first principle calculations to determine the ground state structure of bismuth titanate, based on experimentally observed monoclinic and orthorhombic phases of Bi4Ti3O12. Both of these phases are optimized to zero pressure and lattice parameters were determined as a = 5.4370 Ang, b = 5.4260 Ang, c = 32.6833 Ang and Z = 4 for structure with space group B2cb and a = 5.4289 Ang, b = 5.4077 A…
We have performed first-principles evolutionary searches for all stable titanium nitrides and have found, in addition to the well-known rocksalt-type TiN, new ground states Ti$_3$N$_2$, Ti$_4$N$_3$, Ti$_6$N$_5$ at atmospheric pressure, and Ti$_2$N and TiN$_2$ at higher pressures. The latest nitrogen-rich structure presents encapsulated N$_2$ dumbbells with a N-N distance of 1.348 Å at 60 GPa and TiN$_2$ is predicted to be mechanically stable (quenchable). Our calculations of the mechanical properties (bulk modulus, shear modulus, Young's modulus, Poisson's ratio, and hardness) are in excellent…
We theoretically study the structural stability of $R$Fe$_{12}$ with the ThMn$_{12}$ structure ($R$: rare-earth elements, La, Pr, Nd, Sm, Gd, Dy, Ho, Er, Tm, Lu, Y, or Sc, or group-IV elements, Zr or Hf) based on density functional theory. The formation energy has a strong correlation with the atomic radius of $R$. The formation energy relative to simple substances decreases as the atomic radius decreases, except for $R=$ Sc and Hf, while that relative to $R_{2}$Fe$_{17}$ and bcc Fe has a minimum for $R=$ Dy. The present results are consistent with recent experimental reports in which the part…
A new two-dimensional (2D) material, borophene (2D boron sheet), has been grown successfully recently on single crystal Ag substrates by two parallel experiments [Mannix \textit{et al., Science}, 2015, \textbf{350}, 1513] [Feng \textit{et al., Nature Chemistry}, 2016, \textbf{advance online publication}]. Three main structures have been proposed ($β_{12}$, $χ_3$ and striped borophene). However, the stability of three structures is still in debate. Using first principles calculations, we examine the dynamical, thermodynamical and mechanical stability of $β_{12}$, $χ_3$ and striped borophene. Fr…
Critical to the development of improved solid oxide fuel cell (SOFC) technology are novel compounds with high oxygen reduction reaction (ORR) catalytic activity and robust stability under cathode operating conditions. Approximately 2145 distinct perovskite compositions are screened for potential use as high activity, stable SOFC cathodes, and it is verified that the screening methodology qualitatively reproduces the experimental activity, stability, and conduction properties of well-studied cathode materials. The calculated oxygen p-band center is used as a first principle-based descriptor of …
The actinide elemental metals are scare, often toxic and radio active, causing challenges for both experiments and theory while offering fascinating physics. For practical purposes they are the prevalent building blocks for materials where nuclear properties are of interest. Here, however, we are focusing on fundamental properties of the actinides related to their electronic structure and characteristic bonding in the condensed state. The series of actinides is naturally divided into two segments. First, the set of lighter actinides thorium through plutonium, often referred to as the early act…
In the framework of density functional theory (DFT), the structural and magnetic properties of FeN mono nitride have been investigated using the all electrons augmented spherical wave method (ASW) with a generalized gradient GGA functional for treating the effects of exchange and correlation. Calculation of the energy versus volume in hypothetic rocksalt (RS), zinc-blende (ZB) and wurtzite (W) types structures shows that the RS-type structure is more stable than the others. Spin polarized calculation results at equilibrium volume indicate that the ground state of RS-FeN is ferromagnetic with a…
Thermoelectric materials based on earth-abundant and non-toxic elements are very useful in cost-effective and eco-friendly waste heat management systems. The constituents of SrGaSnH are earth-abundant and non-toxic, thus we have chosen SrSnGaH to study its structural stability and thermoelectric properties by using DFT, DFPT, and semi-classical Boltzmann transport theory. Our elastic and phonons calculations show that the compound has good structural stability. The electronic structure calculation discloses that it is an indirect bandgap (0.63 eV by mBJ+SOC) semiconductor. Light band hole effe…
We have performed density functional calculations of the formation energies of substitutional transition metal (TM) defects, C vacancies, and C interstitial defects in TiC. In addition we have evaluated the migration energy barriers for C atoms in the presence of TM impurities. We find that the solubility of TM impurities taken from the 3d TM series is low and only Sc and V impurities can be dissolved into TiC at equilibrium. In addition, we find that the migration energy barriers of C in TiC are greatly affected by the presence of TM impurities: The migration barriers are generally lower in t…
The structural parameters with stability upon Si incorporation and elastic, electronic, thermodynamic and optical properties of Ti3Al1-xSixC2 (0 \leq x \leq 1) are investigated systematically by the plane wave psedudopotential method based on the density functional theory (DFT). The increase of some elastic parameters with increasing Si-content renders the alloys to possess higher compressive and tensile strength. The Vickers hardness value obtained with the help of Mulliken population analysis increases as x is increased from 0 to 1. The solid solutions considered are all metallic with valenc…
The thermodynamic and physical properties of the Laves phase Fe2Mo have been investigated using the finite-temperature quantum mechanical calculations within the frame of the density functional theory (DFT). All relevant free energy contributions including electronic, vibrational and magnetic excitations are considered. The quasi-harmonic Debye - Gruneisen theory is used. In this work, a new method of searching a thermal expansion path of compounds is proposed. It allows to reduce the problem to a one-dimensional case and minimize the free energy in one variable, in volume. The heat capacity, …
The phonon dispersion relation of NiTi in the simple cubic B2 structure is computed using first-principles density-functional perturbation theory with pseudopotentials and a plane-wave basis set. Lattice instabilities are observed to occur across nearly the entire Brillouin zone, excluding three interpenetrating tubes of stability along the (001) directions and small spheres of stability centered at R. The strongest instability is that of the doubly degenerate M5' mode. The atomic displacements of one of the eigenvectors of this mode generate a good approximation to the observed B19' ground-st…
Phase diagrams of isoelectronic Eu$_{1-x}$Gd$_x$O and Eu$_{1-x}$Gd$_{x}$S quasi-binary alloy systems are constructed using first-principles calculations combined with the standard cluster expansion approach and Monte-Carlo simulations. The oxide system has a wide miscibility gap on the Gd-rich side but forms ordered compounds on the Eu-rich side, exhibiting a deep asymmetric convex hull in the formation enthalpy diagram. The sulfide system has no stable compounds. The large difference in the formation enthalpies of the oxide and sulfide compounds is due to the contribution of local lattice rel…
We report a first principles study based on density functional theory on the structural and electronic properties of transition metal Zr and Hf doped small aluminum clusters with 1 to 7 aluminum atoms. We have used B3PW91 with LANL2DZ basis set in Gaussian 09 package. The stability analysis reveals that the ZrAl4 and HfAl4 structures with C2v symmetry and square pyramid geometry are lowest energy structures. The most stable structures in ZrAl5 and HfAl5 are distorted tetrahedron type structure with symmetry C1. The binding energies per atom for transition metal doped Aln clusters increases wit…
We have performed molecular dynamics simulations using a shell model potential developed by fitting first principles results to describe the behavior of the relaxor-ferroelectric (1-x)PbMg1/3Nb2/3O3-xPbTiO3 (PMN-xPT) as function of concentration and temperature, using site occupancies within the random site model. In our simulations, PMN is cubic at all temperatures and behaves as a polar glass. As a small amount of Ti is added, a weak polar state develops, but structural disorder dominates, and the symmetry is rhombohedral. As more Ti is added the ground state is clearly polar and the system …
We report total energy calculations for different crystal structures of NaNbO$_3$ over a range of unit cell volumes using the all-electron full-potential (L)APW method. We employed both the local-density approximation (LDA) and the Wu-Cohen form of the generalized gradient approximation (GGA-WC) to test the accuracy of these functionals for the description of the complex structural behavior of NaNbO$_3$. We found that LDA not only underestimates the equilibrium volume of the system but also predicts an incorrect ground state for this oxide. The GGA-WC functional, on the other hand, significant…
The energy differences between the face-centered cubic (FCC) and hexagonal closed packed (HCP) structures of the argon (Ar) crystal are studied using the first-principles electronic-structure approach at the level of random phase approximation (RPA) plus renormalized single exitation (rSE) correction. By treating both structures at equal footing (i.e., employing the same computational supercell and k grid sampling), our RPA+rSE calculations show that, at zero temperature, the FCC structure is lower in energy than the HCP structure over a wide pressure range. The influence of zero-point energy …
Recently, Fang et al. have predicted a high ZT of 1.54 in TaSbRu alloys at 1200 K from first-principles without considering spin-orbit interaction, accurate electronic structure, details of phonon scattering, and energy-dependent holes relaxation time. Here, we report the details of structural stability and thermoelectric performance of Bi-Substituted p-type TaSbRu from first-principles calculations considering theses important parameters. This indirect bandgap semiconductor (Eg=0.8 eV by TB-mBJ+SOC) has highly dispersive and degenerate valence bands, which lead to a maximum power factor, 3.8 …
Multicomponent nitrides are a hot research topic in the search of hard coatings. The effect of substitutions on the phase stabilities, magnetic, and elastic properties of $Al_{1-x-y}Cr_{x}Ti_{y}N$ $(0\leq x,y\leq1)$ was studied using first principles calculations based on the density functional theory. These calculations provide the lattice parameter, formation energy, mixing enthalpy and elastic constants. The calculated values are in good agreement with experiments and compare well with other theoretical results. A magnetic transition from antiferromagnetic to ferromagnetic state occurs at c…
