Ab initio investigation of the substitution effects of 2p elements on the electronic structure of γ-Fe4X (X = B, C, N, and O) in the ground state

2016 ◽  
Vol 31 (2) ◽  
pp. 202-212 ◽  
Author(s):  
Antônio Vanderlei dos Santos ◽  
Carlos Ariel Samudio Pérez
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Ground State ◽  
Substitution Effects ◽  
Image Position

Abstract

scholarly journals Magnetic Ground State and Electronic Structure of Binary Mn2Sb Compound from Ab Initio Calculations

Proceedings ◽  
2020 ◽  
Vol 67 (1) ◽  
pp. 15
Author(s):  
Evgenii D. Chernov ◽  
Alexey V. Lukoyanov
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Ground State ◽  
Spin Projection ◽  
Magnetic Ground State ◽  
First Order Phase Transition ◽  
Magnetocaloric Properties ◽  
Ab Initio Approach ◽  
Long Range Ordering ◽  
First Order Phase

Manganese antimonide Mn2−xMxSb, where M is a 3d transition metal, is a prominent binary material due to its high Curie temperature and magnetocaloric properties accompanying the M-induced first-order phase transition for various compositions. In this work, we employed a modern ab initio approach to analyze the magnetic ground state and electronic structure of Mn2Sb for various types of long-range ordering. In the electronic structure of Mn2Sb, it was found to possess the semi-metallic properties with a gap in the minority spin projection.

Ab initio electronic structure and direct dynamics simulations of CH3OCl

2009 ◽  
Vol 87 (7) ◽  
pp. 1022-1029
Author(s):  
Stephanie Y. Y. Wong ◽  
Pierre-Nicholas Roy ◽  
Alex Brown
Keyword(s):  
Electronic Structure ◽  
Excited State ◽  
Ab Initio ◽  
Ground State ◽  
Basis Set ◽  
Ab Initio Molecular Dynamics ◽  
Basis Sets ◽  
Excitation Energies ◽  
Direct Dynamics ◽  
Ab Initio Electronic Structure

The ground (X1A′) and two lowest lying excited singlet states (11A″ and 21A′) of methyl hypochlorite have been examined using ab initio electronic structure techniques to validate computationally efficient methods, upon which direct dynamics can be based, versus high-level ones, for which direct dynamics would be intractable. Ground-state equilibrium geometries and vibrational frequencies determined using density functional theory (DFT) with the 6-31G(d) basis set are tested against coupled-cluster theory (CCSD(T)) results from the literature. Vertical excitation energies and transition dipole moments calculated at the complete active space self-consistent field CASSCF/6-31+G(d) level of theory are benchmarked against multireference configuration interaction (MRCI) results with the aug-cc-pVXZ (X = D, T, Q) family of basis sets. The excited-state gradients that will govern the classical dynamics are compared for CASSCF/6-31+G(d) versus MRCI/aug-cc-pVXZ (X = D, T). To carry out the ab initio molecular dynamics (AIMD), existing electronic structure codes have been interfaced with the molecular modelling toolkit (MMTK), an open-source program library for molecular simulation applications. We use two examples to demonstrate the use of direct dynamics in MMTK: a canonical ground-state trajectory to sample positions and momenta, and an excited-state microcanonical trajectory based on CASSCF. The work presented here forms the basis for future study of the photodissociation of CH3OCl. As well, the implementation of AIMD within MMTK provides a useful tool for examining a variety of other research problems.

scholarly journals Electronic Structure Study of Divanadium Complexes with Rigid Covalent Coordination: Potential Molecular Qubits with Slow Spin Relaxation

2021 ◽  
Author(s):  
Stephen Sproules
Keyword(s):  
Electronic Structure ◽  
Spin Relaxation ◽  
Ground State ◽  
Electronic Structures ◽  
Structure Study ◽  
Ligand Shell

The electronic structures of homovalent [V2(μ-S2)2(R2dtc)4] (R = Et, iBu) and mixed-valent [V2(μ-S2)2(R2dtc)4]+ are reported here. The soft-donor, eight-coordinate ligand shell combined with the fully delocalised ground state provides a...

Electronic structure and optical properties of CuWO4: An ab initio study

2012 ◽  
Vol 63 ◽  
pp. 163-167 ◽  
Author(s):  
M.V. Lalić ◽  
Z.S. Popović ◽  
F.R. Vukajlović
Keyword(s):  
Optical Properties ◽  
Electronic Structure ◽  
Ab Initio ◽  
Ab Initio Study

Effect of Chromium and Vanadium on Nanolayered Ternary Carbides: AB Initio Study

2009 ◽  
Vol 609 ◽  
pp. 239-242
Author(s):  
A.E. Merad ◽  
M.B. Kanoun
Keyword(s):  
Electronic Structure ◽  
Total Energy ◽  
Ab Initio ◽  
Structural Parameters ◽  
Ab Initio Study ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Full Relaxation ◽  
Relaxation Procedure ◽  
Ternary Carbides

The Cr2AlC and V2AlC nanolayered ternary carbides are studied by performing APW-lo ab initio total energy calculations within the recent Wu-Cohen generalized gradient approximation GGA. Using full relaxation procedure of the volume and the atomic positions we obtained the structural parameters and electronic structure of the optimization hexagonal. Results were compared with the experimental ones. Interesting features are deduced. In fact, we have shown why these materials are conductors.

Magnetic Ground State and Electronic Structure Calculations of PbMnO3 Using DFT

2014 ◽  
Vol 895 ◽  
pp. 420-423 ◽  
Author(s):  
Sathya Sheela Subramanian ◽  
Baskaran Natesan
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Fermi Level ◽  
Ground State ◽  
Density Functional ◽  
Electronic Structure Calculations ◽  
Magnetic Ground State ◽  
Electronic Band ◽  
Structure Calculations ◽  
Centrosymmetric Structure

Structural optimization, magnetic ground state and electronic structure calculations of tetragonal PbMnO3have been carried out using local density approximation (LDA) implementations of density functional theory (DFT). Structural optimizations were done on tetragonal P4mm (non-centrosymmetric) and P4/mmm (centrosymmetric) structures using experimental lattice parameters and our results indicate that P4mm is more stable than P4/mmm. In order to determine the stable magnetic ground state of PbMnO3, total energies for different magnetic configurations such as nonmagnetic (NM), ferromagnetic (FM) and antiferromagnetic (AFM) were computed for both P4mm and P4/mmm structures. The total energy results reveal that the FM non-centrosymmetric structure is found to be the most stable magnetic ground state. The electronic band structure, density of states (DOS) and the electron localization function (ELF) were calculated for the stable FM structure. ELF revealed the distorted non-centrosymmetric structure. The band structure and DOS for the majority spins of FM PbMnO3showed no band gap at the Fermi level. However, a gap opens up at the Fermi level in minority spin channel suggesting that it could be a half-metal and a potential spintronic candidate.

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