Linear Muffin-tin Orbital Method Research Articles

An ab initio study of filled skutterudites EuOs4Sb12

The study of structural, elastic, thermodynamic and electronic properties of filled skutterudites EuOs4Sb12 is presented using the full-potential linear muffin-tin orbital method based on the density functional theory. As exchange–correlation potential, we used the local density and local spin density approximation. The equilibrium lattice parameters, bulk modulus, elastic constants and band structure energy of filled skutterudites EuOs4Sb12 are calculated and systematically compared to the available theoretical and experimental data. The total energy variation as a function of strain is used to determine the independent elastic constant and its pressure dependence. The effect of pressure P and temperature T on the lattice parameter, bulk modulus, Debye temperature and the heat capacity of EuOs4Sb12 is investigated for the first time. The electronic band structure shows that EuOs4Sb12 presents a metallic character.

Anionic Doping and Cationic Site Preference in CaYb4Al2Sb6- xGe x ( x = 0.2, 0.5, 0.7): Origin of the Enhanced Seebeck Coefficient and the Structural Transformation.

Three Zintl phase compounds belonging to the CaYb4Al2Sb6- xGe x ( x = 0.2, 0.5, 0.7; nominal compositions) system with various Ge-doping contents were successfully synthesized by arc-melting and were initially crystallized in the Ba5Al2Bi6-type phase (space group Pbam, Pearson codes oP26). However, after post-heat treatment at an elevated temperature, the originally obtained crystal structure was transformed into the homeotypic Ca5Ga2Sb6-type structure according to powder and single-crystal X-ray diffraction analyses. Two types of crystal structures share some isotypic structural moieties, such as the one-dimensional anionic chains formed by ∞1[Al2Sb8] and the void-filling Ca2+/Yb2+ mixed cations, but the slightly different spatial arrangements in each unit cell make these two structural types distinguishable. This series of title compounds is originally investigated to examine whether anionic p-type doping using Ge can successfully enhance thermoelectric (TE) properties of the Yb-rich CaYb4Al2Sb6- xGe x series even after the phase transition from the Ba5Al2Bi6-type to the Ca5Ga2Sb6-type phase. More interestingly, we also reveal that the given structural transformation is triggered by the particularly different site-preference of Ca2+ and Yb2+ among three available cationic sites in each structure type, which is significantly affected by thermodynamic conditions of this system. Band structure and density of states analyses calculated by density functional theory using the tight-binding linear muffin-tin orbital method also prove that the Ge-doping actually increases band degeneracies and the number of resonant peaks near the Fermi level resulting in the improvement of Seebeck coefficients. Electron localization function analyses for the (0 1 0) sliced-plane and the 3D isosurface nicely illustrates the distortion of the paired-electron densities due to the introduction of Ge. The systematic TE property measurements imply that the attempted anionic p-type doping is indeed effective to improve the TE characteristics of the title CaYb4Al2Sb6- yGe y system.

Microscopic origin of ferromagnetism in the trihalides CrCl3 and CrI3

Microscopic origin of the ferromagnetic (FM) exchange coupling in CrCl$_3$ and CrI$_3$, their common aspects and differences, are investigated on the basis of density functional theory combined with realistic modeling approach for the analysis of interatomic exchange interactions. We perform a comparative study based on the pseudopotential and linear muffin-tin orbital methods by treating the effects of electron exchange and correlation in GGA and LSDA, respectively. The results of ordinary band structure calculations are used in order to construct the minimal tight-binding type models describing the behavior of the magnetic Cr $3d$ and ligand $p$ bands in the basis of localized Wannier functions, and evaluate the effective exchange coupling ($J_{\rm eff}$) between two Cr sublattices employing four different technique: (i) Second-order Green's function perturbation theory for infinitesimal spin rotations of the LSDA (GGA) potential at the Cr sites; (ii) Enforcement of the magnetic force theorem in order to treat both Cr and ligand spins on a localized footing; (iii) Constrained total-energy calculations with an external field, treated in the framework of self-consistent linear response theory. We argue that the ligand states play crucial role in the ferromagnetism of Cr trihalides, though their contribution to $J_{\rm eff}$ strongly depends on additional assumptions, which are traced back to fundamentals of adiabatic spin dynamics. Particularly, by neglecting ligand spins in the Green's function method, $J_{\rm eff}$ can easily become antiferromagnetic, while by treating them as localized, one can severely overestimate the FM coupling. The best considered approach is based on the constraint method, where the ligand states are allowed to relax in response to each instantaneous reorientation of the Cr spins, controlled by the external field.

Structural and magnetic properties of the RAl0.2Ge2 compounds (R = Tb, Dy, Ho, Er, Tm)

The structural and magnetic properties of the RAl0.2Ge2 (R = Tb-Tm) germanides were studied by X-ray and neutron diffraction, scanning electron microscopy and magnetometric techniques. The compounds crystallize in the CeNiSi2-type crystal structure (space group Cmcm). Magnetic measurements reveal an antiferromagnetic ordering below TN equal to 38 K (R = Tb), 23 K (Dy), 9 K (Ho) and 6.5 K (Er), and no magnetic ordering in the Tm-compound down to 1.9 K. Based on the neutron diffraction data the magnetic structures can be described by the propagation vector k = (0.4714(2), 0, 0.3128(2)) for TbAl0.2Ge2 and k = (0.4858(5), 0, 0.3214(6)) for DyAl0.2Ge2 while in HoAl0.2Ge2 and ErAl0.2Ge2 a simple collinear antiferromagnetic ordering of the G-type was observed. The electronic structures of the title compounds were calculated using the tight-binding linear muffin-tin orbital (TB-LMTO) method.

Electronic structure and x-ray magnetic circular dichroism in the multiferroic oxide h−YbFeO3

Hexagonal ferrites ($h\text{\ensuremath{-}}R{\mathrm{FeO}}_{3}$, $R$ = Sc, Y, Ho-Lu) have recently been identified as a new family of multiferroic complex oxides. We study electronic and magnetic properties of $h\text{\ensuremath{-}}{\mathrm{YbFeO}}_{3}$ ferrite within the density-functional theory using the generalized gradient approximation (GGA) with consideration of strong Coulomb correlations $(\mathrm{GGA}+U)$ in the framework of the fully relativistic spin-polarized Dirac linear muffin-tin orbital band-structure method. The $4f$ electrons of Yb are explicitly treated as valence electrons. The x-ray absorption spectra and x-ray magnetic circular dichroism (XMCD) at the Yb ${M}_{4,5}$, Fe ${L}_{2,3}$, and O $K$ edges were investigated theoretically. The calculated results are in good agreement with experimental data. We found that the $\mathrm{GGA}+U$ approach with Hubbard ${U}_{\mathrm{eff}}=6.1\phantom{\rule{0.16em}{0ex}}\mathrm{eV}$ and 3.3 eV for Yb and Fe, respectively, well describes the XMCD spectra at the Yb ${M}_{4,5}$, Fe ${L}_{2,3}$, and O $K$ edges.

First principle calculations of hydrostatic pressure effect on the Kondo behavior and magnetic properties of CePdBi

In this research, the effect of hydrostatic pressure on the magnetic properties and Kondo behavior of CePdBi compound is studied. To this aim, the pressure dependence of Ce-magnetic moment and hybridization between Ce-4f localized electrons and conduction electrons are investigated. The calculations are performed by using full-potential linear muffin-tin orbital (FP-LMTO) method within density functional theory framework. The exchange-correlation potential is treated within generalized gradient approximation (GGA) and GGA plus U (GGA+U) where U is Hubbard correlation term. The results show that by applying pressure, the hybridization between Ce-4f localized electrons and conduction electrons and consequently the Kondo interaction change; but different behaviors are observed at the positive and negative pressures.

DFT calculations of structural, optoelectronic and thermodynamic properties of BxAl1-xP alloys

The structural, optoelectronic and thermodynamic properties of the ternary alloys BxAl1-xP are investigated using the Full-potential linear muffin-tin orbital (FP-LMTO) method within density functional theory (DFT) in the zinc-blende structure. The exchange and correlation potentials are treated by the local density approximation (LDA) and generalized gradient approximations (GGA). The ground state properties of BxAl1-xP are determined and compared with the available data. The electronic structure have been investigated and discussed in details. The optical constants, including the dielectric function ε(w) and the refractive index n(w) are calculated and we found that our compounds are potential usefulness in optoelectronic applications. Furthermore, we have analyzed the thermodynamic properties by the quasi-harmonic Debye model.

Electronic Band Structure of Aluminium Nitride and Gallium Nitride Crystallizing in the Wurtzite and Zinc Blende Structures

We have studied the electronic band structure of aluminium nitride and gallium nitride crystallizing in the wurtzite and zinc blende structures. We have presented theoretical study of atom and orbital projected partial density of state for the group third nitrides. We have compared the energy distribution of electronic states in valence and conduction bands as calculated by means of linear muffintin orbital method. The direct comparison with the appropriate density of state was presented to indicate the extent to which we got direct information about allowed electron states by considering the positions of the maxima and minima of the intensity in spectra. The influence of the core level width and spectrometer broadening was also considered. The good agreement between structures observed in spectra and structures in the calculated density of state allowed for consistent analysis of results. We have compared the amounts of bonding and antibonding states near the band edges for different choices of cations and crystal structures. Since the device applications are based mainly on wurtizite type nitride, particular attention was given to this phase. We examined for wultzite structure the level of anisotropy in the formed chemical bonds. Two kinds of bonds π and σ are connected directly with bond lengths. We examined the amount of electronic states available for optical transition as a function of crystal structure, crystallographic direction and presence of cation semicore states. The hydridization between d and p states for different cations and nitrogen were studied. We found that d-p interaction affected the valence band edge and influenced magnitude of the fundamental gap. The obtained results were compared with previously obtained results of theoretical and experimental work and were found in good agreement.

Band structure calculation and rietveld refinement of nanoscale GdFeO3 with affirmation of Jahn Teller's distortion on electric and magnetic properties

We report the meticulous study of freshly synthesized rare earth element substituted R-FeO3 (R-Gd) orthoferrite via co-precipitation route and subsequent sintering. The R-FeO3 powder sample is characterized by X-ray Diffractometer (XRD) for the investigation of crystal structure and is confirmed as orthorhombic with space group Pbnm structure. Nanoparticle dimension is captured by Scanning Electron microscope (SEM). Magnetic character of the sample is examined using vibrating sample magnetometer (VSM), it discloses a nearly linear magnetisation behaviour (paramagnetic behaviour). Dielectric studies and electric Polarization (PE loop) are investigated. A shift is observed in the dielectric constant εr from 250 °C to 300 °C. The Rietveld refinement of the crystal structure from the powder XRD confirms GdFeO3 is distorted at octahedral site of FeO6. This distortion is ascertained as weak Jahn -Teller's distortion leads to the unsaturated electric polarization. The electronic properties, total and partial density of states of GdFeO3 are studied and calculated using Tight - Binding Linear Muffin-Tin Orbital (TBLMTO) method with the Atomic Sphere Approximation (ASA). The band gap of the GdFeO3 is found to be 0.32 eV.

Electronic structure and x-ray magnetic circular dichroism in the hyperhoneycomb iridate β−Li2IrO3

We studied the electronic, magnetic, and optical properties of $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{Li}}_{2}{\mathrm{IrO}}_{3}$ insulator within the density-functional theory using the generalized gradient approximation taking into account strong Coulomb correlations (GGA+$U$) in the framework of the fully relativistic spin-polarized Dirac linear muffin-tin orbital band-structure method. The x-ray absorption spectra and x-ray magnetic circular dichroism (XMCD) at the Ir ${L}_{2,3}$ edges were investigated theoretically from first principles. The calculated results are in good agreement with experimental data. We found that the GGA+$U$ approach with Hubbard ${U}_{\text{eff}}=1.5\phantom{\rule{4pt}{0ex}}\mathrm{eV}$ well describes the optical spectra and XMCD spectra at the Ir ${L}_{2,3}$ edges. We investigated the electronic structure of $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{Li}}_{2}{\mathrm{IrO}}_{3}$ under pressure from first principles. The hyperhoneycomb iridate $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{Li}}_{2}{\mathrm{IrO}}_{3}$ is on the border of the magnetic ordering with relatively weak Coulomb electron-electron correlations. The $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{Li}}_{2}{\mathrm{IrO}}_{3}$ undergoes a pressure-induced structural and magnetic phase transitions at ${P}_{c}=4.4$ GPa with symmetry lowering to the monoclinic $C2/c$. The structural phase transition is accompanied by a dimerization of the previously equally long $x/y$ Ir-Ir bonds. We find remarkable nonmagnetic ground states of $\ensuremath{\beta}\text{\ensuremath{-}}{\mathrm{Li}}_{2}{\mathrm{IrO}}_{3}$ at ${P}_{c}$, with a concomitant electronic phase transition from a Mott insulator to band insulators. We found that ${J}_{\text{eff}}=1/2$ states are still dominant in the low-energy region in high-pressure monoclinic $C2/c$ structure.

Spin-disorder resistivity of random fcc-NiFe alloys

The spin-disorder resistivity (SDR) of a disordered fcc-(${\mathrm{Ni}}_{1\ensuremath{-}x},{\mathrm{Fe}}_{x}$) alloy is determined from first principles. We identify the SDR at and above the critical temperature with the residual resistivity of the corresponding paramagnetic state evaluated in the framework of the disordered local moment (DLM) model. The underlying electronic structure is determined by means of the tight-binding linear muffin-tin orbital method, which employs the coherent potential approximation (CPA) to describe both the DLM state and the chemical disorder in alloys. An extension of the DLM fixed-spin moment method for two independent magnetic moments is used and combined with the paramagnetic lattice gas entropy to determine local moments by minimizing the corresponding free energy. The effect of phonon scattering is included through the mapping of static atomic displacements into a multicomponent random alloy which is then treated in the CPA. Finally, the Kubo-Greenwood-CPA approach is employed to estimate the SDR. We also address the problem of the validity of the Matthiessen rule at the Curie point. Good agreement of calculated and measured SDR is obtained over the whole studied concentration range; the results point to the importance of nonzero Ni magnetic moments in the limit of pure nickel.

Theoretical study of structural, electronic and optical properties of ScxTl1-xP ternary alloys and (ScP)n/(TlP)n superlattices by FP-LMTO method

The Full Potential Linear Muffin-Tin Orbital (FP-LMTO) method has been used to investigate structural and electronic properties of ScP and TlP binary compounds, their ScxTl1-xP ternary alloys and (ScP)n/(TlP)n superlattices for specific cases of x = 0.25, 0.5, 0.75 and n = 1, 2, 3 in the framework of the density functional theory (DFT) within the local density approximation (LDA). The ground-state properties are determined in the cubic Zinc-blende phase (ZnS).The electronic band structures of ScxTl1-xP ternary alloy were calculated in the Zinc-blende phase and the material has a semi-conductor behavior with a direct band gap for x = 0.25 and an indirect band gap for x = 0.5 and 0.75.In studying the possibility to obtain new materials (ScP)n/(TlP)n, the results show that these materials are semiconductors with an indirect band gap for n = 1 and a direct band gap for n = 2 and 3.The optical properties were calculated for only three materials; Sc0.25Tl0.75P, (ScP)2/(TlP)2 and (ScP)3/(TlP)3 which have a direct band gap.

Band gap behavior of thallium phosphide and gallium phosphide binary compounds and Gax Tl1-x P ternary alloys

Full-potential linear muffin-tin orbitals method has been implanted within density functional theory and within local density approximation. The structural and electronic properties of GaP and TlP binary compounds and their ternary alloys Gax Tl1-x P (x = 0,25, 05 or 0.75) in the zinc-blende structure were investigated and calculations obtained results gave reasonable agreements with other published data.

Influence ofp-Type Double-Doping on the Crystals and Electronic Structures of Two Polar Intermetallics: La4.57(1)Li0.43Ge3.80(3)In0.20and Nd4.32(1)Li0.68Ge3.87(3)In0.13

Two quaternary polar intermetallic compounds La4.57(1)Li0.43Ge3.80(3)In0.20 and Nd4.32(1)Li0.68Ge3.87(3)In0.13 were synthesized using a conventional high temperature synthetic method as we attempted to introduce the p-type double-doping of Li and In for RE and Ge in the RE5-xLixGe4-y (RE = rare-earth metals) system, and their crystal structures were characterized by single crystal X-ray diffraction experiments. The two title compounds crystallize in the orthorhombic space group Pnma (Pearson code oP16, Z = 4) with six crystallographically independent asymmetric atomic sites and adopt the Gd5Si4-type structure. Overall crystal structures of two isotypic title compounds can be described as a 1:1 assembly of the hypothetical 2-dimensional (2D) RE2(RE/Li)(In/Ge)2 layered structure adopting the Mo2FeB2-type structure and the dumbbell-shaped inter-slab (In/Ge)2 dimers bridging two such neighboring 2D layers along the crystallographic b-axis direction. The observed “direction selective” structural transformation from the Sm5Ge4-type to the Gd5Si4-type structure can be understood as a result of the simultaneous double-doping by the relatively smaller amount of Li substitution for La at the RE3 site than that in the La4LiGe4 and the partial In substitution for Ge at both of the M1 and M3 sites. The site-preference of In for two particular anionic sites were thoroughly studied using four hypothetical La4LiGe3In models having different atomic arrangements by the tight-binding linear muffin-tin orbital (TB-LMTO) method. The overall electronic structure and individual chemical bonding influenced by the given double-doping were also discussed on the basis of the density of states (DOS) and crystal orbital Hamilton population (COHP) curves analyses.

LDA + DMFT and LDA + U study of the electronic and magnetic properties of DyFeSi

Considering the strong correlation between 4f electrons in the rare earths has major effect on the calculated electronic and magnetic properties of compounds including rare earths, as neglecting this strong correlation in density functional theory (DFT) leads to the failing DFT for a proper description of mentioned properties. In this study, to consider the strong correlation between 4f electrons in Dy atom of DyFeSi compound, local Coulomb repulsion between 4f electrons, U, are treated both statically as in the LDA + U approximation and dynamically as in the dynamical mean-field theory in the Hubbard-I approximation (LDA + DMFT[HI]). In this regards, we apply first principle density functional calculation by using full potential linear muffin-tin orbital (FP-LMTO) method to present a comparative study between the calculated electronic and magnetic properties of DyFeSi within LDA + U and LDA + DMFT[HI] approaches and show that the LDA + DMFT[HI] approach presents so much better results compared to the LDA + U approach. In the magnetic properties we find that the calculation within LDA + DMFT[HI] reproduces the Dy magnetic moments in accordance to the observations and standard model of rare earth with the best accuracy. In the electronic properties we show that LDA + U just produces narrow energy bands of 4f-electrons and it is not able to produce atomic multiples features of 4f valance bands, while LDA + DMFT[HI] approach shows peaks caused by the formation of atomic multiples of the Dy atoms in DyFeSi compound.

Intricate Li-Sn Disorder in Rare-Earth Metal-Lithium Stannides. Crystal Chemistry of RE3Li4- xSn4+ x (RE = La-Nd, Sm; x < 0.3) and Eu7Li8- xSn10+ x ( x ≈ 2.0).

Reported are the syntheses, crystal structures, and electronic structures of six rare-earth metal-lithium stannides with the general formulas RE3Li4- xSn4+ x (RE = La-Nd, Sm) and Eu7Li8- xSn10+ x. These new ternary compounds have been synthesized by high-temperature reactions of the corresponding elements. Their crystal structures have been established using single-crystal X-ray diffraction methods. The RE3Li4- xSn4+ x phases crystallize in the orthorhombic body-centered space group Immm (No. 71) with the Zr3Cu4Si4 structure type (Pearson code oI22), and the Eu7Li8- xSn10+ x phase crystallizes in the orthorhombic base-centered space group Cmmm (No. 65) with the Ce7Li8Ge10 structure type (Pearson code oC50). Both structures can be consdered as part of the [RESn2] n[RELi2Sn] m homologous series, wherein the structures are intergrowths of imaginary RESn2 (AlB2-like structure type) and RELi2Sn (MgAl2Cu-like structure type) fragments. Close examination the structures indicates complex occupational Li-Sn disorder, apparently governed by the drive of the structure to achieve an optimal number of valence electrons. This conclusion based on experimental results is supported by detailed electronic structure calculations, carried out using the tight-binding linear muffin-tin orbital method.

Pressure Induced Structural Phase Transition, Metallization and Superconductivity in RbBr

The structural phase transition, metallization and superconductivity of the simple alkali bromide, Rubidium bromide (RbBr) is investigated through their band structures. Under high pressure RbBr undergoes a structural phase transition from the NaCl structure (B1) to the CsCl structure (B2). The band structure, density of states (DOS) and total energy are computed as a function of volume for both B1 and B2 phases using the full potential linear muffin-tin orbital (FP-LMTO) method. The ground state properties and band gap values are compared with the experimental results. The pressure corresponding to structural phase transition from NaCl structure (B1) to the CsCl structure (B2) is 0.028 Mbar in RbBr. The metallization pressure P M is 1.172 Mbar. The superconducting transition temperatures (Tc) of RbBr is obtained as a function of pressure for both NaCl and CsCl structures. The highest Tc estimated is 2.151 K and the corresponding pressure is 4 Mbar in the NaCl structure and 0.819 K in the CsCl structure. It is also confirmed that the metallization, structural phase transition and onset of superconductivity do not occur simultaneously in ionic compounds. DOI: http://dx.doi.org/10.17807/orbital.v10i2.1125

First-principles calculations of the band ordering conversion in the [formula omitted] compounds

Topological insulators (Tls) are new kinds of quantum's materials states discovered recently, with insulating bulk band gaps and topologically protected metallic surface states; they are immensely investigated due to their promising characteristics for spintronic and quantum computing applications. In this work, we study the potential of Tl property in inverses Heusler compounds (LaxSc2−xRuPb) with x = 0, 1 and 2, by first-principles calculations within the full-potential linear muffin-tin orbital (FP-LMTO) computational approach method as implemented in the computer code (LMTART), which is based on the density functional theory (DFT). We used the local-density approximation (LDA) for the term of the exchange and correlation potential (XC). We investigate the topological ordering of quaternary inverse Heusler XX’YZ according to the possible X and X′ sites combination, and we focus that the trivial semiconductors compounds in x = 0, 2 with the positive energy difference (ΔE=EΓ6−EΓ8) exhibit a non trivial candidates in x = 1 with EΓ6−EΓ8<0.

Structure and Chemical Bonding of the Li-Doped Polar Intermetallic RE₂In1-xLixGe₂ (RE = La, Nd, Sm, Gd; x = 0.13, 0.28, 0.43, 0.53) System.

Four polar intermetallic compounds belonging to the RE2In1−xLixGe2 (RE = La, Nd, Sm, Gd; x = 0.13(1), 0.28(1), 0.43(1), 0.53(1)) system have been synthesized by the traditional solid-state reaction method, and their crystal structures have been characterized by single-crystal X-ray diffraction (SXRD) analyses. The isotypic crystal structures of four title compounds adopt the Mo2FeB2-type structure having the tetragonal space group P4/mbm (Z = 2, Pearson code tP40) with three crystallographically independent atomic sites and can be simply described as a pile of the identical 2-dimensioanl (2D) RE2In1-xLixGe2 slabs stacked along the c-axis direction. The substituting Li atom shows a particular site preference for replacing In at the Wyckoff 2a site rather than Ge at the Wyckoff 4g in this crystal structure. As the size of a used rare-earth metal decreases from La3+ to Gd3+ throughout the title system, the Ge-Ge and Ge-In/Li bond distances, both of which consist of the 2D anionic Ge2(In/Li) layer, gradually decrease resulting in the reduction of a unit cell volume. A series of theoretical investigations has been performed using a hypothetical structure model Gd2In0.5Li0.5Ge2 by tight-binding linear muffin-tin orbital (TB-LMTO) method. The resultant densities of states (DOS) value at the Fermi level (EF) suggests a metallic conductivity for this particular composition, and this calculation result is in a good agreement with the formal charge distribution assigning two extra valence electrons for a metal-metal bond in the conduction band. The thorough analyses of six crystal orbital Hamilton population (COHP) curves representing various interatomic interactions and an electron localization function (ELF) diagram indicating the locations of paired-electron densities are also provided in this article.

Electronic structure properties of new equiatomic CoCuMnZ (Z=In, Sn, Sb) quaternary Heusler alloys: An ab-initio study

The electronic structure, elastic, magnetic and exchange coupling properties of new equiatomic quaternary Heusler alloys CoCuMnZ (for Z = In, Sn, Sb) have been studied using the full-potential linear muffin-tin orbital method. Total energy calculations show that formation of these alloys are energetically favorable and that they are stable in the ferromagnetic phase. Total density of states establish that CoCuMnIn and CoCuMnSn possess metallic behavior at equilibrium lattice constant and show half metallicity on lattice compression. CoCuMnSb is a true half metallic at the equilibrium lattice constants with an indirect band gap of ∼0.5 eV. The calculated values of elastic constants show that CoCuMnIn/Sn also have mechanical stability. In CoCuMnZ, Co-Mn, Mn-Mn and Mn-Co couple ferromagnetically resulting in high Curie temperature in these alloys.