Deciphering the origin of variation in the spin ground state and oxidation state of a {Mn19} cluster on a Au(111) surface: is the Au(111) surface innocent?

2019 ◽  
Vol 55 (57) ◽  
pp. 8238-8241 ◽  
Author(s):  
Rizwan Nabi ◽  
Gopalan Rajaraman
Keyword(s):  
Oxidation State ◽  
Ground State ◽  
Exchange Coupling ◽  
Coupling Constants ◽  
Structural Distortions ◽  
Spin Ground State

Modeling the structure of a {Mn19} cluster on an Au(111) surface reveals that exchange coupling constants vary grossly upon adsorption due to surface-induced structural distortions. This leads to significant variations in the ground state S values.

Electronic and Magnetic Properties of Interstitial 3d Impurities in Silicon

1985 ◽  
Vol 46 ◽  
Author(s):  
H. Katayama-Yoshida ◽  
Alex Zunger
Keyword(s):  
Magnetic Properties ◽  
Ground State ◽  
Hyperfine Coupling ◽  
Coupling Constants ◽  
Self Consistent ◽  
G Value ◽  
First Time ◽  
Chemical Trends ◽  
3D Impurities ◽  
Spin Ground State

AbstractSelf-consistent spin-unrestricted all-electron Green's function calculations are reported for the first time for a series of interstitial 3d impurities in silicon. The calculations, performed within the selfinteraction- corrected local-spin-density fromalism show: (i) not all 3d impurities follow Hund's rule: Tio, Ti−, Vo, V+ and Co2+ have a low-spin ground state, (ii) the angular momentum part gL of g-value is quenched due to p-d hybridization effects, (iii) covalency explains also the chemical trends in the central hyperfine coupling constants, (iii) chemical trends in donor andacceptor transitions are reproduced and are consistent with a high-spin to lowspin transition at the low-Z end and high-Z end of the 3d series, (iv) A number of predictions are offered.

Assessing the Calculation of Exchange Coupling Constants and Spin Crossover Gaps Using the Approximate Projection Model to Improve Density Function Calculations

2019 ◽  
Author(s):  
Xianghai Sheng ◽  
Lee Thompson ◽  
Hrant Hratchian
Keyword(s):  
Density Functional Theory ◽  
Exchange Coupling ◽  
Density Functional ◽  
Spin Crossover ◽  
Coupling Constants ◽  
Spin Projection ◽  
Coupling Constant ◽  
Projection Model ◽  
Functional Theory

This work evaluates the quality of exchange coupling constant and spin crossover gap calculations using density functional theory corrected by the Approximate Projection model. Results show that improvements using the Approximate Projection model range from modest to significant. This study demonstrates that, at least for the class of systems examined here, spin-projection generally improves the quality of density functional theory calculations of J-coupling constants and spin crossover gaps. Furthermore, it is shown that spin-projection can be important for both geometry optimization and energy evaluations. The Approximate Project model provides an affordable and practical approach for effectively correcting spin-contamination errors in molecular exchange coupling constant and spin crossover gap calculations.

scholarly journals f-Electron and Magnetic Ordering Effects in Nickelates LaNiO2 and NdNiO2: Remarkable Role of The Cuprate-Like 3dx2-y2 Band

2020 ◽  
Author(s):  
Jianwei Sun ◽  
Ruiqi Zhang ◽  
Christopher Lane ◽  
Bahadur Singh ◽  
Johannes Nokelainen ◽  
...  
Keyword(s):  
Ground State ◽  
Exchange Coupling ◽  
Density Functional ◽  
High Temperature Superconductivity ◽  
Parent Compound ◽  
Magnetic Ordering ◽  
Striking Similarity ◽  
Infinite Layer ◽  
Open Questions

Abstract Recent discovery of superconductivity in the doped infinite-layer nickelates has renewed interest in understanding the nature of high-temperature superconductivity more generally. The low-energy electronic structure of the parent compound NdNiO2, the role of electronic correlations in driving superconductivity, and the possible relationship betweeen the cuprates and the nickelates are still open questions. Here, by comparing LaNiO2 and NdNiO2 systematically within a parameter free density functional framework, all-electron first-principles framework, we reveal the role Nd 4f-electrons in shaping the ground state of pristine NdNiO2. Strong similarities are found between the electronic structures of LaNiO2 and NdNiO2, except for the effects of the 4f-electrons. Hybridization between the Nd 4f and Ni 3d orbitals is shown to significantly modify the Fermi surfaces of various magnetic states. In contrast, the competition between the magnetically ordered phases depends mainly on the gaps in the Ni dx2-y2 band, so that the ground state in LaNiO2 and NdNiO2 turns out to be striking similarity to that of the cuprates. The d - p band-splitting is found to be much larger while the intralayer 3d ion-exchange coupling is smaller in the nickelates compared to the cuprates. Our estimated value of the on-site Hubbard U is similar to that in the cuprates, but the value of the Hund's coupling JH is found to be sensitive to the Nd magnetic moment. The exchange coupling J in NdNiO2 is only half as large as in the curpates, which may explain why Tc in the nickelates is half as large as the cuprates.

Microwave Spectrum and Nuclear Quadrupole Coupling of 2-Chloropyridine

1987 ◽  
Vol 42 (2) ◽  
pp. 197-206 ◽  
Author(s):  
M. Meyer ◽  
U. Andresen ◽  
H. Dreizler
Keyword(s):  
Excited State ◽  
Ground State ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Vibrationally Excited ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Mo Theory

The microwave spectrum of 2-chloropyridine, 2-Cl(C5H4N), has been studied to determine the 35Cl, 37Cl and 14N nuclear quadrupole coupling constants. The results are discussed within a simple MO theory. We propose an approximate r0-structure under certain assumptions. In addition to the ground state we observed one vibrationally excited state of both chlorine isotopic species of 2-chloropyridine.

DFT Computational Rationalization of an Unusual Spin Ground State in an Mn12 Single-Molecule Magnet with a Low-Symmetry Loop Structure

2005 ◽  
Vol 117 (6) ◽  
pp. 919-923 ◽  
Author(s):  
Dolos Foguet-Albiol ◽  
Ted A. O'Brien ◽  
Wolfgang Wernsdorfer ◽  
Brian Moulton ◽  
Michael J. Zaworotko ◽  
...  
Keyword(s):  
Single Molecule ◽  
Ground State ◽  
Loop Structure ◽  
Single Molecule Magnet ◽  
Low Symmetry ◽  
Spin Ground State

A [3Fe–3S]3+ cluster with exclusively μ-sulfide donors

2016 ◽  
Vol 52 (6) ◽  
pp. 1174-1177 ◽  
Author(s):  
Yousoon Lee ◽  
Ie-Rang Jeon ◽  
Khalil A. Abboud ◽  
Ricardo García-Serres ◽  
Jason Shearer ◽  
...  
Keyword(s):  
Mössbauer Spectroscopy ◽  
Ground State ◽  
Hyperfine Coupling ◽  
Mossbauer Spectroscopy ◽  
Variable Temperature ◽  
Coupling Constants ◽  
Hyperfine Coupling Constants ◽  
Mößbauer Spectroscopy ◽  
Pyramidal Geometry ◽  
Anisotropic Hyperfine

A [3Fe–3(μ-S)]3+ cluster is reported in which each ferric center has a distorted trigonal pyramidal geometry, with an S = 1/2 ground state for the cluster and unusually anisotropic hyperfine coupling constants as determined by variable temperature magnetometry and Mössbauer spectroscopy.

Targeted construction of azido-bridged Ni4complexes with decisive effect of µ-1,3-azide torsion on the spin ground state

2006 ◽  
pp. 3458-3465 ◽  
Author(s):  
Serhiy Demeshko ◽  
Guido Leibeling ◽  
Sebastian Dechert ◽  
Franc Meyer
Keyword(s):  
Ground State ◽  
Decisive Effect ◽  
Spin Ground State

Strong Ferromagnetic Interactions in[V8O14(H−2taci)2]: An Unprecedented Large Spin Ground State for a Vanadyl Cluster

2004 ◽  
Vol 43 (26) ◽  
pp. 3436-3439 ◽  
Author(s):  
Kaspar Hegetschweiler ◽  
Bernd Morgenstern ◽  
Jon Zubieta ◽  
Pamela J. Hagrman ◽  
Nicola Lima ◽  
...  
Keyword(s):  
Ground State ◽  
Ferromagnetic Interactions ◽  
Large Spin ◽  
Spin Ground State

Possibility for an intermediate-spin ground state in the charge-transfer materialSrCoO3

1995 ◽  
Vol 51 (17) ◽  
pp. 11501-11506 ◽  
Author(s):  
R. H. Potze ◽  
G. A. Sawatzky ◽  
M. Abbate
Keyword(s):  
Charge Transfer ◽  
Ground State ◽  
Intermediate Spin ◽  
Spin Ground State
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