scholarly journals First-Principles Study on Stability and Magnetism ofNimAln(m=1–3,n=1–9) Clusters

2013 ◽  
Vol 2013 ◽  
pp. 1-9
Author(s):  
Xiao Zhang ◽  
Bao-Xing Li ◽  
Zhi-wei Ma ◽  
Jiao-jiao Gu
Keyword(s):  
Ground State ◽  
First Principles ◽  
Population Analysis ◽  
Magnetic Moments ◽  
Three Dimensional ◽  
The Other ◽  
Mulliken Population Analysis ◽  
Mixed Species ◽  
Mulliken Population ◽  
Ground State Structures

The investigation on the structures, stabilities, and magnetism ofNimAln(m=1–3,n=1–9) clusters has been made by using first principles. We found some new ground-state structures which had not been found before. These mixed species prefer to adopt three-dimensional (3D) structures starting from four atoms. All the ground-state structures for the Ni-Al clusters are different from those of the corresponding pure Al clusters with the same number of atoms except for three atoms. The Mulliken population analysis shows that some charges transfer from the Al atoms to the Ni atoms.NiAln(n = odd number) cations, Ni2Al6neutral, Ni2Al1and Ni3Al cations and anions, and Ni3Al5anion have the magnetic moments of 2 μB. The magnetic moments of NiAl4and NiAl6cluster neutrals and cations are 2 μBand 3 μB, respectively. All the other cluster neutrals and ions do not have any nontrivial magnetic moments. The 3d electrons in Ni atoms are mainly responsible for the magnetism of the mixed Ni-Al clusters.

STABLE STRUCTURES, ELECTRIC AND MAGNETIC PROPERTIES OF NANOPARTICLES COn(n = 1-6) CLUSTERS: FIRST-PRINCIPLES CALCULATIONS

2013 ◽  
Vol 27 (15) ◽  
pp. 1362007
Author(s):  
JUN LIU ◽  
SHENG-BIAO TAN ◽  
HUI-NING DONG
Keyword(s):  
Magnetic Properties ◽  
Ground State ◽  
First Principles ◽  
Lower Energy ◽  
Magnetic Moments ◽  
Molecular Orbitals ◽  
First Principles Calculations ◽  
Half Metallicity ◽  
Ground State Structures ◽  
Stable Structures

The ground state geometric structures of the nanoparticles or clusters CO n(n = 1-6) were given based on the first-principles calculations. Then the magnetic properties of the clusters CO n(n = 1-6) and ( CO n)-2(n = 1-6) were calculated in system. Results show that their ground state structures are closely related to the numbers of O-ions. These clusters have no magnetic moments and half-metallicity if they are electroneutral. However, they have magnetic moments if they have positive or negative charges. The total magnetic moments of the clusters ( CO n)-2(n = 1-6, but n≠3) are all 2.0000 μB, and all their ions have contributions to the total magnetic moments. The main reason is that the molecular orbitals with lower energy filled with paired electrons and the molecular orbitals with higher energy are occupied by two electrons in parallel.

Structures, electronic and magnetic properties of the MnnS and Mnn−1S2 (n = 1–6) clusters

2019 ◽  
Vol 33 (22) ◽  
pp. 1950254 ◽  
Author(s):  
Zhi Li ◽  
Zhen Zhao ◽  
Qi Wang ◽  
Tong-Tong Shi
Keyword(s):  
Magnetic Properties ◽  
Ground State ◽  
First Principles ◽  
Steel Industry ◽  
Population Analysis ◽  
Total Spin ◽  
Spontaneous Generation ◽  
Mulliken Population ◽  
Electronic And Magnetic Properties ◽  
Homo Lumo

To understand sulfide inclusions in the steel industry, the structures, stabilities, electronic and magnetic properties of the Mn[Formula: see text]S and Mn[Formula: see text]S2 (n=1–6) clusters are investigated by using first-principles. The results show that the S atoms prefer to occupy the outside surface center of the Mn[Formula: see text] (n = 3–6) clusters. Chiral isomers are occurred to the Mn5S2 isomers. The Mn2S, Mn2S2 clusters are more stable than their neighbors. However, the MnS, S2, and Mn5I2 clusters possess higher dynamic stability than their neighbors by the HOMO–LUMO gaps. The Mn[Formula: see text]S and Mn[Formula: see text]S2 (n = 1–6) clusters prefer to spontaneous generation by Gibbs free energy. A few 4s orbital electrons of Mn atoms transferred to the S atoms by Mülliken population analysis. For the other Mn[Formula: see text]S (n = 1–6) clusters, the spin density (17.256) of the ground-state Mn6S clusters is the largest. For the Mn[Formula: see text]S2 (n = 1–6) clusters, the total spin (9.604) of the ground-state Mn2S2 cluster is the largest.

Theoretical study of the geometrical and electronic properties of Be2Mg+ n (n = 1–11) clusters

2019 ◽  
Vol 9 (7) ◽  
pp. 778-785 ◽  
Author(s):  
Ben-Chao Zhu ◽  
Zhang Yu ◽  
Wang Ping ◽  
Lu Zeng ◽  
Shuai Zhang
Keyword(s):  
Electronic Properties ◽  
Ground State ◽  
Density Functional ◽  
Population Analysis ◽  
Dft Method ◽  
Mulliken Population ◽  
Functional Theory ◽  
Fragmentation Energy ◽  
Average Binding Energy ◽  
Ground State Structures

By using Density Functional Theory (DFT) method at the B3LYP/6-311G level, the structures, stabilities, and electronic properties of cationic Be2Mg+ n (n = 1–11) clusters have been systematically studied. The optimized geometry show that the ground state structures of cationic Be2Mg+ n (n = 1–11) clusters favor 3D structures except n = 1, 2. Furthermore, the average binding energy E b, the second-order energy differences Δ2E, the fragmentation energy Ef and the HOMO-LUMO energy Egap of the ground state of cationic Be2Mg– n (n = 1–11) clusters are calculated, the final results indicate that Be2Mg+6 and Be2Mg+9 clusters have a higher stability than other clusters. Additionally, the NCP, NEC and Mulliken population analysis reveal that the charges in cationic Be2Mg+ n (n = 1–11) clusters transfer from Mg atom to Be atoms, and strong sp hybridizations are presented in Be atoms of Be2Mg+ n clusters. Finally, the polarizability analysis indicates that the nuclei and electronic clouds of clusters are affected by external field with the increase of cluster size.

First-principles study on the thermodynamic, mechanical and magnetic properties of the Fe-N phases

2020 ◽  
Vol 34 (17) ◽  
pp. 2050156
Author(s):  
Zhi Li ◽  
Zhen Zhao ◽  
Tong-Tong Shi ◽  
Xi-Min Zang
Keyword(s):  
First Principles ◽  
Population Analysis ◽  
Magnetic Moments ◽  
Iron Nitrides ◽  
Anisotropic Behavior ◽  
Ductile Phase ◽  
Mulliken Population ◽  
Debye Temperatures ◽  
Brittle Phase ◽  
Formation Energies

To clear the intermetallic Fe-N phases, how to effect the strength and magnetic features of iron nitrides thin films, the thermodynamic, mechanical and magnetic attributes of the Fe-N phases have been calculated at Perdew, Burke and Enzerhof (PBE) level. The results show that the [Formula: see text] and [Formula: see text] phases are more stable than the other considered Fe-N phases by the formation energies. [Formula: see text] and [Formula: see text] phases are metastable at 0 K, which can be further decomposed into other more stable phases with temperature decreasing, i.e., [Formula: see text] and [Formula: see text]. [Formula: see text] is the only brittle phase, while [Formula: see text] is the most ductile phase. The [Formula: see text] possesses the highest thermal conductivity by Debye temperatures. The [Formula: see text] possesses the highest anisotropic behavior by [Formula: see text], [Formula: see text] and [Formula: see text] values. The [Formula: see text] and FeN phases possess higher average magnetic moments (MM) than their neighbors. The [Formula: see text] has stronger ionic bond by Mülliken population analysis.

CO Adsorption on the AunS(n=1~6) Clusters: The First-Principles Study

2011 ◽  
Vol 341-342 ◽  
pp. 42-47
Author(s):  
Shui Lian Chi ◽  
Ming Chen ◽  
Song Lin Peng
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Population Analysis ◽  
Co Adsorption ◽  
Bimetallic Clusters ◽  
Mulliken Population Analysis ◽  
Mulliken Population ◽  
Functional Theory ◽  
Au Clusters ◽  
Adsorption Energies

Density functional theory (DFT) calculations are performed to investigate CO bonded on the AunS (n=1~6) bimetallic clusters. It is found that the adsorption energies of CO on the AunS(n=1~6) clusters are greater than those on the pure Au clusters of corresponding sizes. This means that doped S atom can enhance CO adsorption on the Au clusters. Furthermore, through the Mulliken population analysis, we can see that charges transfer from the Au clusters to S atom, while charges donate to the Au clusters from the CO in CO/AunS sytem.

scholarly journals Ni Oxidation State and Ligand Saturation Impact on the Capability of Octaazamacrocyclic Complexes to Bind and Reduce CO2

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4139
Author(s):  
Barbora Vénosová ◽  
Ingrid Jelemenská ◽  
Jozef Kožíšek ◽  
Peter Rapta ◽  
Michal Zalibera ◽  
...  
Keyword(s):  
Quantum Theory ◽  
Oxidation State ◽  
Central Atom ◽  
Population Analysis ◽  
Mulliken Population Analysis ◽  
Mulliken Population ◽  
Theoretical Methods ◽  
Ni Oxidation ◽  
Shed Light

Two 15-membered octaazamacrocyclic nickel(II) complexes are investigated by theoretical methods to shed light on their affinity forwards binding and reducing CO2. In the first complex 1[NiIIL]0, the octaazamacrocyclic ligand is grossly unsaturated (π-conjugated), while in the second 1[NiIILH]2+ one, the macrocycle is saturated with hydrogens. One and two-electron reductions are described using Mulliken population analysis, quantum theory of atoms in molecules, localized orbitals, and domain averaged fermi holes, including the characterization of the Ni-CCO2 bond and the oxidation state of the central Ni atom. It was found that in the [NiLH] complex, the central atom is reduced to Ni0 and/or NiI and is thus able to bind CO2 via a single σ bond. In addition, the two-electron reduced 3[NiL]2− species also shows an affinity forwards CO2.

Importance of Thermally Induced Magnetic Excitations in First-Principles Simulations of Elastic Properties of Transition Metal Alloys

2012 ◽  
Vol 190 ◽  
pp. 291-294
Author(s):  
Igor A. Abrikosov ◽  
Marcus Ekholm ◽  
Alena V. Ponomareva ◽  
Svetlana A. Barannikova
Keyword(s):  
Transition Metal ◽  
Elastic Properties ◽  
Ground State ◽  
First Principles ◽  
Magnetic Moments ◽  
Metal Alloys ◽  
Face Centered Cubic ◽  
Magnetic Ground State ◽  
Magnetic Excitations ◽  
Transition Metal Alloys

We demonstrate the importance of accounting for the complex magnetic ground state and finite temperature magnetic excitations in theoretical simulations of structural and elastic properties of transition metal alloys. Considering Fe72Cr16Ni12face centered cubic (fcc) alloy, we compare results of first-principles calculations carried out for ferromagnetic and non-magnetic states, as well as for the state with disordered local moments. We show that the latter gives much more accurate description of the elastic properties for paramagnetic alloys. We carry out a determination of the magnetic ground state for fcc Fe-Mn alloys, considering collinear, as well as non-collinear states, and show the sensitively of structural and elastic properties in this system to the detailed alignment between magnetic moments. We therefore conclude that it is essential to develop accurate models of the magnetic state for the predictive description of properties of transition metal alloys.

scholarly journals Effect of Doping on the Photoelectric Properties of Borophene

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Chunhong Zhang ◽  
Zhongzheng Zhang ◽  
Wanjun Yan ◽  
Xinmao Qin
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Population Analysis ◽  
Covalent Bond ◽  
Infrared Light ◽  
Chemical Bonds ◽  
Mulliken Population Analysis ◽  
Mulliken Population ◽  
Photoelectric Properties ◽  
Effect Of Doping

Borophene is a new type of two-dimensional material with a series of unique and diversified properties. However, most of the research is still in its infancy and has not been studied in depth. Especially in the field of semiconductor optoelectronics, there is no related research on the modulation of photoelectric properties of borophene. In this work, we focus on the effect of doping on the photoelectric properties of borophene by using the first-principles pseudopotential plane wave method. We calculate the geometric structure, electronic structure, Mulliken population analysis, and optical properties of impurity (X = Al, Ga) doped α-sheet borophene. The results show that α-sheet borophene is an indirect band gap semiconductor with 1.396 eV. The band gap becomes wider after Al and Ga doping, and the band gap values are 1.437 eV and 1.422 eV, respectively. Due to the orbital hybridization between a small number of Al-3p electrons and Ga-4p state electrons and a large number of B 2p state electrons near the Fermi level, the band gap of borophene changes and the peak value of the electron density of states reduces after doping. Mulliken population analysis shows that the B0-B bond is mainly covalent bond, but there is also a small amount of ionic bond. However, when the impurity X is doped, the charge transfer between X and B atoms increases significantly, and the population of the corresponding X-B bonds decreases, indicating that the covalent bond strength of the chemical bonds in the doped system is weakened, and the chemical bonds have significant directionality. The calculation of optical properties shows that the static dielectric constant of the borophene material increases, and the appearance of a new dielectric peak indicates that the doping of Al and Ga can enhance the ability of borophene to store electromagnetic energy. After doping, the peak reflectivity decreases and the static refractive index n0 increases, which also fills the gap in the absorption of red light and infrared light by borophene materials. The research results provide a basis for the development of borophene materials in the field of infrared detection devices. The above results indicate that doping can modulate the photoelectric properties of α-sheet borophene.

FIRST-PRINCIPLES STUDY OF STRUCTURES AND ELECTRONIC PROPERTIES FOR NITRIDE-DOPED ALUMINUM CLUSTERS

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2380-2385 ◽  
Author(s):  
BAOLIN WANG ◽  
DALING SHI ◽  
XIAOSHUANG CHEN ◽  
GUANGHOU WANG ◽  
JIJUN ZHAO
Keyword(s):  
Genetic Algorithm ◽  
Electronic Properties ◽  
Atomic Structure ◽  
Ground State ◽  
First Principles ◽  
Cluster Size ◽  
Aluminum Clusters ◽  
Structural And Electronic Properties ◽  
Ground State Structures ◽  
Homo Lumo

By using Gaussian98 package at BPW91 6-31g(d,p) level combined a genetic algorithm (GA) simulation, we have studied the lowest energy structural and electronic properties of the Al n N ( n =2-13) clusters. The ground-state structures, the charge transfers from Al to N site, HOMO-LUMO gap and the covalent, ionic and metallic nature with cluster size and atomic structure are investigated. Al 7 N , Al 9 N and Al 12 N cluster is found particularly stable among the Al n N clusters.

Discovery of new ground state structures for Li4Mn2O5 and V2O5 from first principles

2019 ◽  
Vol 159 ◽  
pp. 454-459 ◽  
Author(s):  
Arihant Bhandari ◽  
Puneet Jindal ◽  
Jishnu Bhattacharya
Keyword(s):  
Ground State ◽  
First Principles ◽  
Ground State Structures
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