Structural,electronic,and magnetic properties in FeAlAu_n(n=1–6)clusters:A first-principles study

The geometries,electronic and magnetic properties of the trimetallic clusters Fe Al Aun(n = 1–6) are systematically investigated using density functional theory(DFT).A number of new isomers are obtained to probe the structural evolutions.All doped clusters show larger relative binding energies than pure Aun+2partners,indicating that doping with Fe and Al atoms can stabilize the Aun clusters.The highest occupied molecular orbital–lowest unoccupied molecular orbital(HOMO–LUMO) gaps,vertical ionization potentials and vertical electron affinities are also studied and compared with those of pure gold clusters.Magnetism calculations demonstrate that the magnetic moments of Fe Al Aun clusters each show a pronounced odd–even oscillation with the number of Au atoms.     

A density functional theory study on size-dependent structures,stabilities,and electronic properties of bimetallic M_nAg_m(M=Na,Li;n + m≤7) clusters

The equilibrium geometries,relative stabilities,and electronic properties of Mn Agm(M=Na,Li;n + m ≤ 7) as well as pure Ag n,Na n,Li n(n ≤ 7) clusters are systematically investigated by means of the density functional theory.The optimized geometries reveal that for 2 ≤ n ≤ 7,there are significant similarities in geometry among pure Ag n,Na n,and Li n clusters,and the transitions from planar to three-dimensional configurations occur at n = 7,7,and 6,respectively.In contrast,the first three-dimensional(3D) structures are observed at n + m = 5 for both Na n Ag m and Li n Ag m clusters.When n + m ≥ 5,a striking feature is that the trigonal bipyramid becomes the main subunit of Li n Ag m.Furthermore,dramatic odd-even alternative behaviours are obtained in the fragmentation energies,secondorder difference energies,highest occupied and lowest unoccupied molecular orbital energy gaps,and chemical hardness for both pure and doped clusters.The analytic results exhibit that clusters with an even electronic configuration(2,4,6) possess the weakest chemical reactivity and more enhanced stability.     

Structure,stability and electronic properties of SrSi_n(n= 1–12) clusters::Density-functional theory investigation

Geometric structures, stabilities, and electronic properties of SrSin(n = 1–12) clusters have been investigated using the density-functional theory within the generalized gradient approximation. The optimized geometries indicate that one Si atom capped on SrSin 1structure and Sr atom capped Sinstructure for difference SrSinclusters in size are two dominant growth patterns. The calculated average binding energy, fragmentation energy, second-order energy difference, the highest occupied molecular orbital, and the lowest unoccupied molecular orbital(HOMO–LUMO) gaps show that the doping of Sr atom can enhance the chemical activity of the silicon framework. The relative stability of SrSi9is the strongest among the SrSinclusters. According to the mulliken population and natural population analysis, it is found that the charge in SrSin clusters transfer from Sr atom to the Sinhost. In addition, the vertical ionization potential, vertical electron affinity, and chemical hardness are also discussed and compared.     

Geometries, stabilities, and electronic properties of Be-doped gold clusters: a density functional theory study

We have systematically investigated the geometrical structures, relative stabilities and electronic properties of small bimetallic AunBe (n = 1, 2, . . . , 8) clusters using a density functional method at BP86 level. The optimized geometries reveal that the impurity beryllium atom dramatically affects the structures of the Aun clusters. The averaged binding energies, fragmentation energies, second-order difference of energies, the highest occupied-lowest unoccupied molecular orbital energy gaps and chemical hardness are investigated. All of them exhibit a pronounced odd-even alternation, manifesting that the clusters with even number of gold atoms possess relatively higher stabilities. Especially, the linear Au2Be cluster is magic cluster with the most stable chemical stability. According to the natural population analysis, it is found that charge-transferring direction between Au atom and Be atom changes at the size of n = 4.     

Structures,stabilities,and magnetic properties of the Fe_nAu(n=1-12) clusters

The configurations,stabilities,electronic,and magnetic properties of Fe_nAu(n = 1–12) clusters are investigated systematically by using the relativistic all-electron density functional theory with the generalized gradient approximation.The substitutional effects of Au in Fe_(n+1)(n = 1,2,4,5,10–12) clusters are found in optimized structures which keep the similar frameworks with the most stable Fe_(n+1)clusters.And the growth way for Fe_nAu(n = 6–9) clusters is that the Au atom occupies a peripheral position of Fen cluster.The peaks appear respectively at n = 6 and 9 for Fen Au clusters and at n = 5 and 10 for Fe_(n+1)clusters based on the size dependence of second-order difference of energy,implying that these clusters possess relatively high stabilities.The analysis of atomic net charge Q indicates that the charge always transfers from Fe to Au atom which causes the Au atom to be nearly non-magnetic,and the doped Au atom has little effect on the average magnetic moment of Fe atoms in Fen Au cluster.Finally,the total magnetic moment is reduced by 3 μB for each of Fen Au clusters except n = 3,11,and 12 compared with for corresponding pure Fe_(n+1) clusters.     

Density functional study of Al-doped Au clusters

The equilibrium geometries and electronic properties of Au_nAl, up to n=13, have been systematically investigated using the density functional theory. The results show that, for the Au_nAl clusters, two patterns are identified. Pattern one (n=2, 3, 8), the lowest-energy geometries prefer two-dimensional structures. Pattern two (n=4-7, 9--13), the lowest-energy geometries prefer three-dimensional structures. According to the analysis of the binding energy and the fragmentation energy, Au_nAl clusters with odd n are found to be more stable than those with even n. The same trend of alternation can be illuminated according to the computational results in the HOMO--LUMO gap, the ionization potential, and the electron affinities. The Al atom not only changes the structures of pure gold clusters, but also enhances their stabilities. NBO analysis indicates 6s orbital of Au atom hybridizes with 3p orbital of Al atom.     

A density functional theory structures,stabilities, and study on size-dependent electronic properties of bimetallic MnAgm （M=Na,Li; n ＋ m ≤ 7） clusters

The equilibrium geometries, relative stabilities, and electronic properties of MnAgm（M=Na, Li; n ＋ m ≤ 7） as well as pure Agn, Nan, Lin （n ≤ 7） clusters are systematically investigated by means of the density functional theory. The optimized geometries reveal that for 2 ≤ n ≤ 7, there are significant similarities in geometry among pure Agn, Nan, and Lin clusters, and the transitions from planar to three-dimensional configurations occur at n = 7, 7, and 6, respectively. In contrast, the first three-dimensional （3D） structures are observed at n ＋ m = 5 for both NanAgm and LinAgm clusters. When n ＋ m ≥5, a striking feature is that the trigonal bipyramid becomes the main subunit of LinAgm. Furthermore, dramatic odd-even alternative behaviours are obtained in the fragmentation energies, secondorder difference energies, highest occupied and lowest unoccupied molecular orbital energy gaps, and chemical hardness for both pure and doped clusters. The analytic results exhibit that clusters with an even electronic configuration （2, 4, 6） possess the weakest chemical reactivity and more enhanced stability.     

Structure,stability and electronic properties of SrSin （n ： 1-12） clusters： Density-functional theory investigationStructure,stability and electronic properties of SrSin （n ： 1-12） clusters： Density-functional theory investigation

Geometric structures, stabilities, and electronic properties of SrSin （n = 1-12） clusters have been investigated using the density-functional theory within the generalized gradient approximation. The optimized geometries indicate that one Si atom capped on SrSin_ 1 structure and Sr atom capped Sin structure for difference SrSin clusters in size are two dominant growth patterns. The calculated average binding energy, fragmentation energy, second-order energy difference, the highest occupied molecular orbital, and the lowest unoccupied molecular orbital （HOMO-LUMO） gaps show that the doping of Sr atom can enhance the chemical activity of the silicon framework. The relative stability of SrSi9 is the strongest among the SrSin clusters. According to the mulliken population and natural population analysis, it is found that the charge in SrSin clusters transfer from Sr atom to the Sin host. In addition, the vertical ionization potential, vertical electron affinity, and chemical hardness are also discussed and compared.     

Geometries,stabilities, and electronic properties analysis in In_nNi~((0,±1)) clusters: Molecular modeling and DFT calculations

Density functional theory(DFT) with the B3 LYP method and the SDD basis set is selected to investigate In_nNi,In_nNi~-, and In_nNi~+ (n = 1–14) clusters. For neutral and charged systems, several isomers and different multiplicities are studied with the aim to confirm the most stable structures. The structural evolution of neutral, cationic, and anionic In_nNi clusters, which favors the three-dimensional structures for n = 3–14. The main configurations of the In_nNi isomers are not affected by adding or removing an electron, the order of their stabilities is also nearly not affected. The obtained binding energy exhibits that the Ni-doped In_(13) cluster is the most stable species of all different sized clusters. The calculated fragmentation energy and the second-order energy difference as a function of the cluster size exhibit a pronounced even–odd alternation phenomenon. The electronic properties including energy gap(E_g), adiabatic electron affinity(AEA), vertical electron detachment energy(VDE), adiabatic ionization potential energy(AIP), and vertical ionization potential energy(VIP) are studied. The total magnetic moments show that the different magnetic moments depend on the number of the In atoms for charged In_nNi. Additionally, the natural population analysis of In_nNi~((0,±1)clusters is also discussed.     

Density functional theory study of Mg_2Ni_n(n= 1–8) clusters

The density functional theory B3PW91 with LANL2DZ basis sets has been used to study the possible geometries of Mg2Nin(n = 1–8) clusters. For the lowest energy structures of the clusters, stabilities, electronic properties, and natural bond orbital(NBO) are calculated and discussed. The results show that the doped Mg atoms reduce the stabilities of pure Ni clusters. The Mg2Ni2, Mg2Ni4, and Mg2Ni6clusters are more stable than neighboring clusters. The system appears magic number characteristics. In addition, the hybridization phenomenon occurs, owing to the interaction of Mg and Ni. The result of charge transfer is that Ni atom is negative and the Mg atom is positive. We also conclude that the 3p and 4d orbitals of the Ni atom have an effect on the stabilities of the clusters.     

Density functional study of Agn-1Y (n=2-10) clusters

Employing the density functional theory, we investigate the lowest-energy geometric, the stable and the electronic properties of Ag_n-1Y (n=2-10) clusters in this paper. The structural optimization and the frequency analysis are performed at the B3LYP/LANL2DZ level. Meanwhile, the differences in geometry, stability and electronic properties between Ag_n and Ag_n-1Y (n=2-10) clusters are also studied. The results show that for the doping of the yttrium atoms, the structures and the average binding lengths of the Ag_n clusters are greatly changed. In addition, the thermodynamic stabilities of the Ag_n clusters are enhanced generally with the doping of the Y atoms. In addition, the chemical stabilities of the Ag_n-1Y clusters are still improved compared with that of the three-dimensional Ag_n clusters.     

Density functional theory study of MgnNi2 (n=1-6) clusters

The geometries of Mg_nNi₂ (n=1-6) clusters are studied by using the hybrid density functional theory (B3LYP) with LANL2DZ basis sets. For the ground-state structures of Mg_nNi₂ clusters, the stabilities and the electronic properties are investigated. The results show that the groundstate structures and symmetries of Mg clusters change greatly due to the Ni atoms. The average binding energies have a growing tendency while the energy gaps have a declining tendency. In addition, the ionization energies exhibit an odd-even oscillation feature. We also conclude that n=3, 5 are the magic numbers of the Mg_nNi₂ clusters. The Mg₃ Ni₂ and Mg₅Ni₂ clusters are more stable than neighbouring clusters, and the Mg₄Ni₂ cluster exhibits a higher chemical activity.     

A density functional theory study on size-dependent structures, stabilities, and electronic properties of the bimetallic MnAgm (M=Na, Li; n+m ≤ 7) clusters

The equilibrium geometries, relative stabilities, and electronic properties of M_nAg_m (M=Na, Li; n+m≤ 7) as well as pure Ag_n, Na_n, Li_n (n≤ 7) clusters are systematically investigated by means of density functional theory. The optimized geometries reveal that for 2≤ n ≤ 7, there are significant similarities in geometry among pure Ag_n, Na_n, and Li_n clusters, and the transitions from planar to three-dimensional configurations occur at n=7, 7, and 6, respectively. In contrast, the first three-dimensional (3D) structures are observed at n+m=5 for both Na_nAg_m and Li_nAg_m cluters. When n+m ≥ 5, a striking feature is that the trigonal bipyramid becomes the main subunit of Li_nAg_m. Furthermore, dramatic odd-even alternative behaviours are obtained in the fragmentation energies, second-order difference energies, highest occupied and lowest unoccupied molecular orbital energy gaps, and chemical hardness for both pure and doped clusters. The analytic results exhibit that clusters with even electronic configuration (2, 4, 6) possess weakest chemical reactivity and more enhanced stability.     

密度泛函理论研究Run和RunAu(n=1-12)团簇的结构和电子性质

采用密度泛函理论中的广义梯度近似(GGA) 对 Ru_n Au和Ru_n 团簇的几何构型进行优化,并对能量、频率、电子性质和磁性质进行了计算. 结果表明,Ru_n Au团簇的最低能量结构可以通过Au原子代替Ru_n+1团簇中的Ru原子生长而成.除了局域的结构畸变,Ru_n Au和Ru_n+1团簇具有相似的几何结构.二阶能量差分、电离势、亲和势和分裂能表明Ru₅, Ru₈, Ru₅Au, Ru₈Au 是稳定的团簇,Au的掺杂没有改变Ru_n 的相对稳定性.通过电子性质的分析发现,当Au原子掺杂在Ru_n 中,团簇的化学活性增加,且团簇的能隙主要由电子的配对效应决定;对于大多数团簇来说,Au原子掺杂提高了Ru_n Au的磁矩. 关键词： n Au和Ru_n 团簇')" href="#">Ru_n Au和Ru_n 团簇 几何结构 电子性质     

The density functional study of the stabilities,bond characters,static linear polarisabilities,and aromaticities of the ’in-out’ isomerism Hn-60@CnH60（n=70,72,74）

This paper uses the density functional theory to analyse the stabilities,bond characters,static linear polarisabilities,and aromaticities of the ’in-out’ isomerism H n-60 @C n H 60 (n=70,72,74).The binding energies,C-H bond energies,and energy gaps explore that the ’in-out’ isometric perhydrogenation of C n (n=70,72,74) can remarkably improve the stabilities.The static linear polarisabilies of H n-60 @C n H 60 (n=70,72,74) are indeed relative to their shapes,while they show almost nonaromatic character.This study can suggest that the ’in-out’ isometric perhydrogenation of fullerenes could lead to the invention of entirely novel potential hydrogen storage nanomaterials.     

Structures and electronic properties of Mo2nNn（n=1-5）:a density functional study

The lowest-energy structures and the electronic properties of Mo2nNn(n=1-5) clusters have been studied by using the density functional theory(DFT) simulating package DMol 3 in the generalized gradient approximation(GGA).The resulting equilibrium geometries show that the lowest-energy structures are dominated by central cores which correspond to the ground states of Mo n(n = 2,4,6,8,10) clusters and nitrogen atoms which surround these cores.The average binding energy,the adiabatic electron affinity(AEA),the vertical electron affinity(VEA),the adiabatic ionization potential(AIP) and the vertical ionization potential(VIP) of Mo2nNn(n=1-5) clusters have been estimated.The HOMO-LUMO gaps reveal that the clusters have strong chemical activities.An analysis of Mulliken charge distribution shows that charge-transfer moves from Mo atoms to N atoms and increases with cluster size.     

A density-functional theory for (BAs)n clusters (n=1 14): structures, stabilities and electronic properties

This paper investigates the lowest-energy structures,stabilities and electronic properties of (BAs) n clusters (n=1-14) by means of the density-functional theory.The results show that the lowest-energy structures undergo a structural change from two-dimensional to three-dimensional when n=4.With the increase of the cluster size (n 6),the (BAs) n clusters tend to adopt cage-like structures,which can be considered as being built from B 2 As 2 and six-membered rings with B-As bond alternative arrangement.The binding energy per atom,second-order energy differences,vertical electron affinity and vertical ionization potential are calculated and discussed.The caculated HOMO-LUMO gaps reveal that the clusters have typical semiconductor characteristics.The analysis of partial density of states suggests that there are strong covalence and molecular characteristics in the clusters.     

Geometries, stabilities, and electronic properties of gold-magnesium (AunMg) bimetallic clusters

The geometrical structures, relative stabilities, and electronic properties of bimetallic Au_nMg (n=1-8) clusters have been systematically investigated by means of first-principle density functional theory. The results show that the ground-state isomers have planar structures for n=1-7. Here, the calculated fragmentation energies, the second-order difference of energies, the highest occupied-lowest unoccupied molecular orbital energy gaps, and the hardness exhibit a pronounced odd-even alternation, manifesting that the clusters, especially Au₂Mg, with even-number gold atoms have a higher relative stability. On the basis of natural population analysis, the charge transfer and magnetic moment are also discussed.     

WnNim(n+m=8)团簇结构与电子性质的理论研究

采用密度泛函理论(DFT)中的B3LYP方法,在Lanl2dz基组水平上对W_nNi_m(n+m=8)团簇的各种可能构型进行了几何参数全优化,得到了它们的基态构型;并对基态构型的平均结合能、Wiberg键级(WBI)、磁学性质、NBO进行了分析,结果表明:团簇随着W原子数的增多,稳定性增强,n≥5时,结构中都含有纯钨团簇的结构基元;W-W键级高于W-Ni键和Ni-Ni键;W₅Ni₃,W₆Ni₂团簇发生了"磁矩猝灭"的现象;在W,Ni原子内部,轨道电荷发生了转移,产生了"轨道杂化"现象,W,Ni原子之间也发生了电荷转移形成了较强的化学键. 关键词： nNi_m(n+m=8)团簇')" href="#">W_nNi_m(n+m=8)团簇 几何结构 电子性质 密度泛函理论