Density functional theory with alternative spin densities: Application to magnetic systems with localized spins

2004 ◽  
Vol 120 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Ángel J. Pérez-Jiménez ◽  
José M. Pérez-Jordá ◽  
Francesc Illas
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Magnetic Systems ◽  
Spin Densities

Band engineering of borophene superlattice based on zigzag nanoribbons: A DFT study

2020 ◽  
Vol 34 (32) ◽  
pp. 2050359
Author(s):  
Yi Zhang ◽  
Weiwei Ju ◽  
Tongwei Li ◽  
Haisheng Li
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Electronic Properties ◽  
Energy Band ◽  
Density Functional ◽  
Magnetic Moments ◽  
Dft Study ◽  
Functional Theory ◽  
Magnetic Systems ◽  
Band Engineering

By performing density functional theory (DFT) calculations, we demonstrate that periodically repeating heterostructures of zigzag borophene nanoribbons (BNR) of different widths can form stable borophene superlattice (BSL). The energy band structures of BSL can be modulated through modifying the width and length of the segments. A metal-semiconductor transition can be obtained when the length of each segment is lengthened, whereas, the magnetism of BSL is influenced by the width of the segments. In those magnetic systems, the magnetic moments are mainly localized on protruding B atoms located at the edge, while no magnetic moments occur in the center B atoms. The hydrogenated BNR and BSL are further investigated. The hydrogenation can modify the electronic properties of BNR and BSL as well as quench the magnetism. All hydrogenated BNR and BSL are non-magnetic. Our results indicate that great potential exists in these systems for borophene utilization in nanoelectronics and spintronics.

Subsystem density-functional theory for interacting open-shell systems: spin densities and magnetic exchange couplings

2020 ◽  
Vol 224 ◽  
pp. 201-226
Author(s):  
Anja Massolle ◽  
Johannes Neugebauer
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Open Shell ◽  
Broken Symmetry ◽  
Easy Access ◽  
Magnetic Exchange ◽  
Functional Theory ◽  
Spin Densities

Subsystem DFT allows easy access to spin densities for arbitrary broken-symmetry states of radical aggregates.

SPIN DENSITIES AND CURRENTS IN THE ROUTHIAN APPROXIMATION

2006 ◽  
Vol 15 (02) ◽  
pp. 553-559
Author(s):  
JOHANN BARTEL ◽  
KAMEL BENCHEIKH ◽  
PHILIPPE QUENTIN
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Degrees Of Freedom ◽  
Vector Fields ◽  
Semiclassical Approximation ◽  
Spin Current ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Current Densities ◽  
Spin Densities

The structure of spin densities and the associated spin-current densities, induced by the coupling of external vector fields to the orbital and spin degrees of freedom, is studied within the framework of the Extended Thomas-Fermi method, a semiclassical version of the density-functional theory. A special emphasis is put on the rotational case where our approach amounts to perform a semiclassical approximation of the so-called generalized Routhian approach.

A density functional theory study of the free radicals NH2, NF2, NCl2, PH2, PF2, and PCl2

1994 ◽  
Vol 72 (3) ◽  
pp. 695-704 ◽  
Author(s):  
Maggie A. Austen ◽  
Leif A. Eriksson ◽  
Russell J. Boyd
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Local Density ◽  
Basis Set ◽  
Basis Sets ◽  
Functional Theory ◽  
Unpaired Spin ◽  
Non Local ◽  
Local Potentials ◽  
Spin Densities

The linear combination of Gaussian-type orbitals–density functional theory (LCGTO–DFT) approach is used to study geometries and hyperfine structures of a set of neutral radicals. Each of the title molecules is investigated by means of local density approximation calculations, and using the Becke–Perdew and Perdew–Wang–Perdew corrections to the exchange and correlation functionals. The effects of local vs. non-local potentials and of various basis sets are investigated. Total densities and unpaired spin densities are compared. The isotropic couplings are found to be very dependent on the type of exchange functional used, whereas the anisotropic couplings are relatively insensitive to the choice of basis set and functional. In most cases, the Perdew–Wang exchange corrections provide isotropic couplings in satisfactory agreement with experiment.

scholarly journals Multiconfiguration Pair-Density Functional Theory

2021 ◽  
Vol 72 (1) ◽  
pp. 541-564
Author(s):  
Prachi Sharma ◽  
Jie J. Bao ◽  
Donald G. Truhlar ◽  
Laura Gagliardi
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Strongly Correlated Systems ◽  
Background Information ◽  
Total Density ◽  
Strongly Correlated ◽  
Functional Theory ◽  
Correlated Systems ◽  
Pair Density ◽  
Spin Densities

Kohn-Sham density functional theory with the available exchange–correlation functionals is less accurate for strongly correlated systems, which require a multiconfigurational description as a zero-order function, than for weakly correlated systems, and available functionals of the spin densities do not accurately predict energies for many strongly correlated systems when one uses multiconfigurational wave functions with spin symmetry. Furthermore, adding a correlation functional to a multiconfigurational reference energy can lead to double counting of electron correlation. Multiconfiguration pair-density functional theory (MC-PDFT) overcomes both obstacles, the second by calculating the quantum mechanical part of the electronic energy entirely by a functional, and the first by using a functional of the total density and the on-top pair density rather than the spin densities. This allows one to calculate the energy of strongly correlated systems efficiently with a pair-density functional and a suitable multiconfigurational reference function. This article reviews MC-PDFT and related background information.

Density functional theory analyses of bis(bipyridine)ruthenium noninnocent quinonoid and thiolosulfinato complexes containing ligands formally in the semiquinone oxidation state

2009 ◽  
Vol 87 (10) ◽  
pp. 1451-1459 ◽  
Author(s):  
A. B.P. Lever
Keyword(s):  
Density Functional Theory ◽  
Oxidation State ◽  
Electronic Structures ◽  
Continuum Model ◽  
Density Functional ◽  
Open Shell ◽  
Functional Theory ◽  
Polarized Continuum Model ◽  
Spin Densities ◽  
Sulfur Donor

Density functional theory and the polarized continuum model are used to derive the electronic structures of some open-shell, bis(bipyridine)ruthenium complexes bound to noninnocent quinonoid or thiolosulfinato ligands formally in the semiquinone oxidation state. The noninnocent properties of the o-thiolosulfinato ligand are explored and compared with those of the more conventional o-semiquinones with nitrogen, oxygen, and sulfur donor atoms. Spin densities are shown to be fairly localized in the metallocycle ring. It is demonstrated that oxidation of the parent [RuII(bpy)2 (1,2-(S,SO2)–C6H4] species occurs primarily in the metallocycle ring and is localized in the Ru–S0 bond.

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