DFT study on the crystal, electronic and magnetic structures of tantalum based double perovskite oxides Ba2MTaO6 (M = Cr, Mn, Fe) via GGA and GGA + U

How reliable are DFT transition structures? Comparison of GGA, hybrid-meta-GGA and meta-GGA functionals.

There have been many comparisons of computational methods applied to ground states, but studies of organic reactions usually require calculations on transition states, and these provide a different test of the methods. We present calculations of the geometries of nineteen covalent-bond forming transition states using HF and twelve different functionals, including GGA, hybrid-GGA and hybrid meta...

Formation enthalpies by mixing GGA and GGA + U calculations

Study of the structural properties of Co 2 YGe ( Y = Sc , Ti , V , Cr , Mn , Fe ) by GGA method

The structural properties of Co2YGe, a Heusler alloy have been evaluated by first principles density functional theory through total energy calculations at 0 K by the full potential linearized augmented plane wave (FP-LAPW) method as implemented in WIEN2K code. The calculated results were compared with the previously reported results. Generalized gradient approximation (GGA) was used to study t...

(M=Cr,Mn,Fe,Co) by LSDA and LSDA+U

We have implemented a systematic LSDA and LSDA+U study of the double perovskites A2FeReO6 (A=Ba,Sr,Ca) and Sr2MMoO6 (M=Cr,Mn,Fe,Co) for understanding of their intriguing electronic and magnetic properties. The results suggest a ferrimagnetic (FiM) and half-metallic (HM) state of A2FeReO6 (A=Ba,Sr) due to a pdd-π coupling between the down-spin Re5+/Fe3+ t2g orbitals via the intermediate O 2pπ on...

First-principles LDA+U and GGA+U study of cerium oxides: Dependence on the effective U parameter

The electronic structure and properties of cerium oxides CeO2 and Ce2O3 have been studied in the framework of the LDA+U and GGA PW91 +U implementations of density functional theory. The dependence of selected observables of these materials on the effective U parameter has been investigated in detail. The examined properties include lattice constants, bulk moduli, density of states, and formatio...