The structural stability and magnetic properties of the icosahedral Ni13, Ni13^＋1 and Ni13^-1 clusters have been obtained by utilizing all-electron density functional theory with the generalized gradient approximatio...The structural stability and magnetic properties of the icosahedral Ni13, Ni13^＋1 and Ni13^-1 clusters have been obtained by utilizing all-electron density functional theory with the generalized gradient approximations for the exchange-correlation energy. The calculated results show that the ground states of neutral and charged clusters all favour a D3d structure, a distorted icosahedron, due to the Jahn-Teller effect. The radial distortions caused by doping one electron and by doping one hole are opposite to each other. Doping one electron will result in a 1/2 decrease and doping one hole will result in a 1/2 increase of the total spin. Both increasing interatomic spacing and decreasing coordination will lead to an enhancement of the spin magnetic moments for Nil3 clusters.展开更多
Growth modes of the free-standing NiCN （N ≤ 8） and Ni2CN （N ≤ 8） dusters are investigated by the allelectron density functional theory. The results reveal that there are two competing modes for the growth of the...Growth modes of the free-standing NiCN （N ≤ 8） and Ni2CN （N ≤ 8） dusters are investigated by the allelectron density functional theory. The results reveal that there are two competing modes for the growth of these clusters： the linear chain and the ring structure without transannular bonds. The lowest-energy geometries of NiCN （N ≤ 8） are the linear chains with the Ni atom at one end, except for NiC2 and NiCT. The Ni2CN （N ≤ 8） clusters all prefer to the linear chains with the two Ni atoms at the two ends. Miilliken population analysis indicates that the total spin of the lowest-energy cluster show significant odd-even alternation. The NiMCN （M = 1,2） clusters with the even N are one and those with the odd-N are zero.展开更多
The low-energy structures and the electronic and the magnetic properties of small NinTin （n ： 1-6） and NimTin （1 ≤ n ≤ 4, 1≤m ≤ 4, n ≠m） clusters are investigated by performing all-electron calculations base...The low-energy structures and the electronic and the magnetic properties of small NinTin （n ： 1-6） and NimTin （1 ≤ n ≤ 4, 1≤m ≤ 4, n ≠m） clusters are investigated by performing all-electron calculations based on density functional theory. Ground states and several isomers near the ground states are determined for these clusters. The results indicate that the growth of small Ni,nTin clusters prefers to form rich Ti-Ni and Ti Ti bonds. When the percentage of titanium atoms is significantly greater than that of nickel atoms, the nickel atoms are most frequently found above the surface; in contrast, the titanium atoms prefer the bridging sites. A Mulliken spin population analysis indicates that the total spin of titanium-nickel clusters is not always zero.展开更多
We investigate the configurations, electronic structures, and magnetic ordering of MnN （N = 2-13） clusters based on all-electron density functional theory. The Jahn-Teller effect plays an important role in determini...We investigate the configurations, electronic structures, and magnetic ordering of MnN （N = 2-13） clusters based on all-electron density functional theory. The Jahn-Teller effect plays an important role in determining the ground state of certain geometries. The magnetic ordering of the MnN dusters transits from ferromagnetic ordering for the smallest （ N = 2, 3） dusters to a near degeneracy state including ferromagnetic and ferrimagnetic ordering in the vicinity of N = 4-6 and to a clear ferrimagnetic ordering at N = 7 or beyond. N = 6 and 10 are the magic numbers for neutrai MnN （N = 2-13） dusters.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10574036 and 10574037）. and the Hebei Natural Science Foundation （Grant Nos A2004000141 and 2005000143）.
文摘The structural stability and magnetic properties of the icosahedral Ni13, Ni13^＋1 and Ni13^-1 clusters have been obtained by utilizing all-electron density functional theory with the generalized gradient approximations for the exchange-correlation energy. The calculated results show that the ground states of neutral and charged clusters all favour a D3d structure, a distorted icosahedron, due to the Jahn-Teller effect. The radial distortions caused by doping one electron and by doping one hole are opposite to each other. Doping one electron will result in a 1/2 decrease and doping one hole will result in a 1/2 increase of the total spin. Both increasing interatomic spacing and decreasing coordination will lead to an enhancement of the spin magnetic moments for Nil3 clusters.
基金Supported by the National Natural Science Foundation of China under Grant No 10574037, the National Basic Research Programme of China under Grant No 2006CB605101, the Natural Science Foundation of Hebei Province under Grant No A2007000227, and the Doctorial Start-up Fund of Hebei Normal University （L2005B07）. The authors would like to thank Dr N. E. Davison and Dr X. H. Qi for their help with the language.
文摘Growth modes of the free-standing NiCN （N ≤ 8） and Ni2CN （N ≤ 8） dusters are investigated by the allelectron density functional theory. The results reveal that there are two competing modes for the growth of these clusters： the linear chain and the ring structure without transannular bonds. The lowest-energy geometries of NiCN （N ≤ 8） are the linear chains with the Ni atom at one end, except for NiC2 and NiCT. The Ni2CN （N ≤ 8） clusters all prefer to the linear chains with the two Ni atoms at the two ends. Miilliken population analysis indicates that the total spin of the lowest-energy cluster show significant odd-even alternation. The NiMCN （M = 1,2） clusters with the even N are one and those with the odd-N are zero.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10874039)the Natural Science Foundation of Hebei Province of China (Grant Nos. A2009000246 and 2009000243)
文摘The low-energy structures and the electronic and the magnetic properties of small NinTin （n ： 1-6） and NimTin （1 ≤ n ≤ 4, 1≤m ≤ 4, n ≠m） clusters are investigated by performing all-electron calculations based on density functional theory. Ground states and several isomers near the ground states are determined for these clusters. The results indicate that the growth of small Ni,nTin clusters prefers to form rich Ti-Ni and Ti Ti bonds. When the percentage of titanium atoms is significantly greater than that of nickel atoms, the nickel atoms are most frequently found above the surface; in contrast, the titanium atoms prefer the bridging sites. A Mulliken spin population analysis indicates that the total spin of titanium-nickel clusters is not always zero.
基金Supported by the National Natural Science Foundation of China under Grant No 10574036, the National Basic Research Program of China under Grant No 2006CB605101, the Natural Science Foundation of Hebei Province （No A2005000143）, and the Hebei Doctorial Foundation （03547008D and B2004115）.
文摘We investigate the configurations, electronic structures, and magnetic ordering of MnN （N = 2-13） clusters based on all-electron density functional theory. The Jahn-Teller effect plays an important role in determining the ground state of certain geometries. The magnetic ordering of the MnN dusters transits from ferromagnetic ordering for the smallest （ N = 2, 3） dusters to a near degeneracy state including ferromagnetic and ferrimagnetic ordering in the vicinity of N = 4-6 and to a clear ferrimagnetic ordering at N = 7 or beyond. N = 6 and 10 are the magic numbers for neutrai MnN （N = 2-13） dusters.
