The stability of cyclopentadiene is determined using quantum Monte Carlo in both the VMC and DMC variants, HF, CCSD(T), LDA, and the BPW91, B3PW91, BLYP, B3LYP generalized gradient approximation (GGA) density functional theory methods. A comparison with available experimental data shows that the GGAs perform signi®cantly better than LDA and HF for structure optimization. The cyclopentadiene ato...

We investigate the zinc vacancy effects on the electronic structures and magnetic properties of Sc-doped ZnO, by performing first-principles calculations within both GGA + U and Heyd–Scuseria–Ernzerhof hybrid functional methods. We find that Sc impurities stabilize considerably Zn vacancies. The electronic and magnetic analysis shows a half metallic ferromagnetic character with a total magnetic...

The geometry and electronic structure of copper-based p-type delafossite transparent conducting oxides, CuMO(2) (M = In, Ga, Sc), are studied using the generalized gradient approximation (GGA) corrected for on-site Coulomb interactions (GGA + U). The bonding and valence band compositions of these materials are investigated, and the origins of changes in the valence band features between group 3...

First-principle calculations of the electronic structure and magnetic interaction of GaN:Gd have been performed within the generalized gradient approximation (GGA) of the density functional theory with the on-site Coulomb energy U taken into account (also referred to as GGA+U). The ferromagnetic p-d coupling is found to be over 2 orders of magnitude larger than the s-d exchange coupling. The ex...

We extend the previously proposed one-parameter double-hybrid density-functional theory [K. Sharkas, J. Toulouse, and A. Savin, J. Chem. Phys. 134, 064113 (2011)] to meta-generalized-gradient-approximation (meta-GGA) exchange-correlation density functionals. We construct several variants of one-parameter double-hybrid approximations using the Tao-Perdew-Staroverov-Scuseria (TPSS) meta-GGA funct...

We report a combined experimental-computational investigation of the electronic structure of CrO2. We have measured the magneto-optical Kerr spectra of CrO2 at 10 K and 300 K. At 10 K the Kerr signal is significantly enhanced over that obtained at 300 K. We compare the measured Kerr spectra to first-principles theoretical spectra, which we computed using three different approximations to the ex...

We present results of GGA+U calculations for the “d magnet” RbO2, where magnetic properties are due to partially filled oxygen p orbitals. We show that on-site interactions on the oxygen sites lead to a strong tendency towards the formation of an orbitally polarized insulating state, in contrast to the half-metallic behavior predicted for this class of compounds within pure LDA/GGA. The obtaine...

The unique meta-GGA (generalized gradient approximation) exchange functional of Becke and Roussel (BR89) and the correlation functional of Becke related to it (B94) are represented for the first time in an analytical form. All functional derivatives are then obtained analytically, which allows an efficient self-consistent implementation. A brief assessment of this "BR89B94" meta-GGA scheme is m...

We study the electronic structure, magnetization, and thermoelectric properties of CsPd0.875Cr0.125I3 obtained by doping CsPdI3 with atoms 3d transition metal Cr. By applying generalized-gradient-approximation (GGA) GGA + U one, we found that alloy exhibits a completely metallic characteristic. Changes in are determined use BoltzTrap code. The thermal conductivities (k/т), Seebeck coefficients ...