DENSITY FUNCTIONAL STUDY OF STRUCTURE AND STABILITY OF Al7OH CLUSTERS

2010 ◽  
Vol 24 (10) ◽  
pp. 1253-1259
Author(s):  
Q. L. LU ◽  
J. HE ◽  
Q. Q. LUO ◽  
J. G. WAN ◽  
G. H. WANG
Keyword(s):  
Density Functional ◽  
Population Analysis ◽  
Functional Study ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
Large Binding Energy ◽  
High Ionization ◽  
Homo Lumo ◽  
Bonding Characteristic

We studied the structure and electronic properties of Al 7 OH clusters using density functional theory with generalized gradient approximation. OH prefers to the ontop site of Al atoms, and the hollow form is not stable. The Al 7 moieties can keep their structures in ontop form Al 7 OH cluster, while it dramatically changes for bridge form ones. The binding strength between Al 7 and OH are much larger than that of Al 7 I and Al 7 H . The bonding characteristic of Al 7– OH is mainly ionic according to the population analysis. Large binding energy, HOMO–LUMO gap, and high ionization potential imply that Al 7 OH cluster is physically high and chemically stable.

scholarly journals Hydrogen Storage on Beryllium-Coated Toroidal Carbon Nanostructure C120 Modeled with Density Functional Theory

2010 ◽  
Vol 72 ◽  
pp. 188-195 ◽  
Author(s):  
Fray de L. Castillo-Alvarado ◽  
Jaime Ortíz-López ◽  
J.S. Arellano ◽  
Armando Cruz-Torres
Keyword(s):  
Density Functional ◽  
Population Analysis ◽  
Energy Charge ◽  
Carbon Nanostructure ◽  
Generalized Gradient ◽  
Mulliken Population ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
Materials Studio ◽  
Homo Lumo

Ab initio density functional calculations were performed on a toroidal carbon C120 nanostructure with a single beryllium atom bonded to its outer surface. These calculations are based on DFT with the generalized gradient approximation PW91 (Perdew and Wang) as implemented in the Materials Studio v.4.3 code. The Dmol3 module was used to calculate, among others, total energy, charge density, HOMO-LUMO and Mulliken population analysis. On the basis of these results, the beryllium-coated toroidal carbon C120 nanostructure appears to be a good candidate for H2 storage with moderate adsorption energy.

Stability and Physicochemical Principles for Icosahedral Ti12X (X = Li to Xe) Clusters: A DFT Study

2008 ◽  
Vol 8 (5) ◽  
pp. 2475-2478
Author(s):  
M. Salazar-Villanueva ◽  
P. H. Hernandez Tejeda ◽  
J. F. Rivas-Silva ◽  
J. A. Ascencio
Keyword(s):  
Density Functional ◽  
Chemical Affinity ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
Stable Clusters ◽  
The Density Functional Theory ◽  
The Stability ◽  
Chemical Selectivity ◽  
Homo Lumo

Results about stability, electronic structure and characteristic electronic properties are reported for cluster structures based on icosahedra structure with a composition of Ti12X (X = Li to Xe) within the generalized gradient approximation of the density functional theory. It is demonstrated that several elements allow an improvement on the stability of Ti13 by a doping process where the central atoms is substituted. C, Si, P, Co, Ge, Ru and Te lead to the largest gain in energy, while the HOMO-LUMO maximum gap distinguishes to just C, Si, P and Te as the most probable to be found in experimental samples. The analysis included physicochemical study of the most stable clusters to predict chemical affinity and new properties. Results reported here are in agreement with partial studies of Ti12X but because of the considered elements, a new scope is open of possible application mainly in the fields as sensors, catalysis and medicine, where the chemical selectivity is an important parameter.

Density Functional Theory Study of GdnO3 (n=1-5) Clusters

2012 ◽  
Vol 588-589 ◽  
pp. 51-54
Author(s):  
Lin Xu ◽  
Zong Lin Liu ◽  
Hong Kuan Yuan
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Density Functional ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Average Binding Energy ◽  
Generalized Gradient Approximation ◽  
Electronic Configurations ◽  
Homo Lumo

The geometries, stabilities, electronic and magnetic properties of small GdnO3(n=1-5) clusters have been systematically studied by using density functional theory with the generalized gradient approximation. We found that the Gd atoms and O atoms in GdnO3clusters prefer three and two coordination, respectively, which origin from the electronic configurations of Gd and O atoms. The results show that Gd2O3cluster is more stable than its respective neighbors, which is reflected from its high average binding energy and high HOMO-LUMO gap. In addition, we calculate the magnetic properties of GdnO3clusters. The local magnetic moments of the Gd atom in the GdnO3clusters exhibit a weak dependence on the O atoms, which are slightly enhanced with the increasing of the number of Gd atom.

A Density Functional Study of Ho-Doped Sin (n=1-12, 16, and 18) Clusters

2011 ◽  
Vol 130-134 ◽  
pp. 1035-1038
Author(s):  
Zong Lin Liu ◽  
Hong Kuan Yuan ◽  
Hong Chen
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Density Functional ◽  
Functional Study ◽  
Surface Site ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Electronic And Magnetic Properties ◽  
Generalized Gradient Approximation ◽  
The Density Functional Theory

The geometric, electronic, and magnetic properties of Ho-doped Sin (n=1-12, 16, and 18) clusters are studied via the density functional theory with the generalized gradient approximation. The results show that the Ho atom in the most stable HoSin clusters always occupies the surface site. Starting from n=18, the Ho atom abruptly drops into the center of Si frame, forming the Ho-encapsulated Si cages. The stabilities of HoSin clusters increase with increasing size n. The Ho atom in HoSin clusters enhances their chemical activities. Moreover, the magnetisms of HoSin clusters are independent of their geometric structures, and the Si and Ho atoms are antiferromagnetic.

A density functional study on the electronic structure, nature of bonding and reactivity of NO adsorbing Rh0/±n (n = 2–8) clusters

2018 ◽  
Vol 42 (2) ◽  
pp. 1121-1132 ◽  
Author(s):  
Abhijit Dutta ◽  
Paritosh Mondal
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Gas Phase ◽  
Density Functional ◽  
Functional Study ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Density Functional Study ◽  
Generalized Gradient Approximation

Systematic investigations on lowest energy NO adsorbing neutral and ionic Rhn (n = 2–8) clusters in the gas phase are executed with an all electron relativistic method using density functional theory (DFT) within the generalized gradient approximation.

Dissociation of dinitrogen on iron clusters: A detailed study of the Fe16 + N2 case.

2020 ◽  
Author(s):  
Bole Chen ◽  
Gennady L. Gutsev ◽  
Weiguo Sun ◽  
Xiao-Yu Kuang ◽  
Cheng Lu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Basis Set ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Iron Clusters ◽  
Generalized Gradient Approximation

The coalescence of two Fe8N as well as the structure of the Fe16N2 cluster were studied using density functional theory with the generalized gradient approximation and a basis set of...

An Investigation of Half-Metallic Ferromagnets Behavior in Hg2CuTi-Type Heusler Alloy Ti2FeAl by Using GGA

2012 ◽  
Vol 535-537 ◽  
pp. 1291-1294 ◽  
Author(s):  
Xiu De Yang ◽  
Bo Wu ◽  
Song Zhang
Keyword(s):  
Density Functional Theory ◽  
Heusler Alloy ◽  
Density Functional ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Half Metallic ◽  
Generalized Gradient Approximation ◽  
Indirect Exchange ◽  
The Density Functional Theory ◽  
Direct Hybridization

By using generalized gradient approximation (GGA) scheme within the density functional theory (DFT), the electronic and magnetic properties of Hg2CuTi-type Heusler alloy Ti2FeAl were investigated. The results reveal that a 100% spin polarization appears at Fermi level (εF) in Ti2FeAl, and is maintained during lattice range of 5.1Å~6.2Å. Ti2FeAl is one of stable Half-Metallic Ferromagnets (HMF) with a spin-minority gap of 0.5 eV at εF and total magnetic moment of 1μB per unit cell. Our studies also indicate that the competition between RKKY-type indirect exchange and direct hybridization of d-electronic atoms plays a dominating role in determining the magnetism.

Thermoelectric Transport Properties of SrTiO3 Doped with Pm

2018 ◽  
Vol 280 ◽  
pp. 3-8 ◽  
Author(s):  
A. A. Adewale ◽  
Abdullah Chik ◽  
R. Mohd Zaki ◽  
F. Che Pa ◽  
Yeoh Chow Keat ◽  
...  
Keyword(s):  
Transport Properties ◽  
Figure Of Merit ◽  
Density Functional ◽  
Generalized Gradient ◽  
Thermoelectric Figure ◽  
Functional Theory ◽  
Thermoelectric Transport ◽  
Generalized Gradient Approximation ◽  
High Contribution ◽  
Thermoelectric Transport Properties

Thermoelectric properties of SrTiO3doped with 8%Pm at Sr site were investigated using density functional theory and generalized gradient approximation. The transport properties were calculated based on BoltzTraP code at temperature range 300-1200K. In electronic properties study Fermi level were shifted to conduction band region due to high contribution 4f orbital in Pm. Present study thermoelectric figure of merit ZT result was 0.395 at 300K and 0.638 at 1200K. This shows a considerably good value of ZT for SrTiO3as n-type oxide. Compared to previous work, ZT were at the range of 0.21 - 0.37 for temperature of 300-1000K in Pr, La, Ta and Ho.

CO2 Adsorption on the B12N12 Nanocage Encapsulated with Alkali Metals: A Density Functional Study

NANO ◽  
2019 ◽  
Vol 14 (03) ◽  
pp. 1950034
Author(s):  
Ximin Liang ◽  
Qiyan Zhang ◽  
Qinfu Zhao ◽  
He Zhao ◽  
Yifan Feng ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Density Functional ◽  
Alkali Metals ◽  
Large Change ◽  
Functional Study ◽  
Functional Theory ◽  
Metal Atoms ◽  
Adsorption Of Co ◽  
Physical And Chemical ◽  
Homo Lumo

Density functional theory (DFT) calculations have been carried out to study the capacity of the B[Formula: see text]N[Formula: see text] nanocage encapsulated with alkali metals (Li, Na, K) for the CO2 adsorption and activation. It is found that after encapsulating alkali metals, the alkali metal atoms are closer to one side of clusters instead of exactly lying at the center, and a considerable charge transfers from the inner alkali metal atoms to the B[Formula: see text]N[Formula: see text] cage. Besides, the HOMO–LUMO gap (HLG) values of Li@B[Formula: see text]N[Formula: see text], Na@B[Formula: see text]N[Formula: see text] and K@B[Formula: see text]N[Formula: see text] are decreased to about 6[Formula: see text]eV, being much smaller than that of the pristine B[Formula: see text]N[Formula: see text]. Although the geometry structure parameters and the energy differences of M06-2X are slightly different from the ones of [Formula: see text]B97X-D, some identical results of two kinds of functional can be obtained. CO2 can be adsorbed chemically and physically on majority bonds of all the clusters, except for some bonds with large change in bond length and bond indices. The encapsulation of alkali-metal atoms may enhance the physical and chemical adsorption of CO2 on the surface of the clusters, in which Na@B[Formula: see text]N[Formula: see text] and K@B[Formula: see text]N[Formula: see text] are the most powerful physical and chemical adsorbent for CO2, respectively.

Sign in / Sign up

Export Citation Format

Share Document