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1.
Ga6 N6团簇结构性质的理论计算研究   总被引:3,自引:0,他引:3       下载免费PDF全文
在密度泛函理论的基础上,对Ga6N6团簇进行了第一性原理、全电子、从头计算,得到了10种可能的三维空间结构及其电子结构.其中最稳定结构的一对GaN原子的平均结合能为9.748 eV,因此是可能存在的.但与他人计算的Ga3N3和Ga5N5相比,Ga6N6团簇可能不属于"幻数"团簇.最稳定结构的Ga6N6团簇的费米面是部分占有的,能量为EF=-5.2972 eV,因此具有"金属性",但没有自旋磁矩.我们还计算了该结构的Ga6N6团簇的亲和势、电离能和电子跃迁能.这将有助于对GanNn团簇系列的结构和性质随n变化的研究.  相似文献   

2.
BmN (m=1-8)团簇结构和稳定性的密度泛函理论研究   总被引:1,自引:1,他引:0  
使用泛函密度理论的B3LYP 方法,在6-311G*水平上对BmN(m=1-8)团簇的几何结构、电子结构、振动频率等进行了研究。结果表明,以Bm团簇作为设计母体,考虑在不同位置上结合N原子可以较快找到BmN类团簇基态结构;团簇的最稳定结构是平面结构,N原子倾向于在B团簇外端与两个B原子成键。通过对基态结构的平均束缚能和能量二次差分的计算,得到m=2和5的BmN团簇较为稳定。  相似文献   

3.
GanNm+(n=1~8,m=1~2)团簇的结构及稳定性的DFT研究   总被引:2,自引:2,他引:2  
用密度泛函理论(DFT)的B3LYP方法在6-31C*水平上对GanN (n=2~8)和GanN2 (n=1~7)阳离子团簇的几何结构、稳定性和振动频率等进行研究,得到GanN (n=2~8)和GanN2 (n=1~7)阳离子团簇的基态结构.其中,GanN (n=2~8)团簇在总原子数≤6时,其几何结构为平面结构,总原子数>6时,其几何结构为立体结构,N原子位于立体结构的中心;GanN2 (n=2~7)团簇在总原子数≤7时,其基态几何结构为平面结构,总原子数>7时,其基态几何结构为立体结构;原子总数为奇数的团簇Ga4N ,Ga6N ,Ga3N2 和Ga5N2 的基态结构较稳定.  相似文献   

4.
从头计算对GanNm团簇的结构与稳定性的研究   总被引:2,自引:0,他引:2  
用B3LYP-DFT方法对GanN2(n=1~7)和GanN(n=2~8)团簇的结构与稳定性进行了研究.在6-31G*水平上进行了结构优化和频率分析,得到了GanN2(n=1~7)和GanN(n=2~8)团簇的基态结构.在GanN(n=2~8)团簇的基态几何结构中,N原子处在分子结构的中心;在GanN2(n=1~3)团簇中,N—N键比Ga—N键强;在GanN2(n=4~7)团簇中存在Ga3N单元和Ga4N单元.在GanN2(n=1~7)和GanN(n=2~8)团簇中,Ga4N2,Ga6P2,Ga3N,Ga5N和Ga7N较其它团簇稳定.  相似文献   

5.
GaN及其Ga空位的电子结构   总被引:8,自引:0,他引:8       下载免费PDF全文
何军  郑浩平 《物理学报》2002,51(11):2580-2588
用团簇埋入自洽计算法对宽禁带半导体GaN的电子结构进行了自旋极化的、全电子、全势场的从头计算,得到了与实验值符合的GaN晶体禁带宽度以及价带中N2p带、N2s带和Ga3d带之间的相对位置.在此基础上Ga空位计算(无晶格畸变)显示,Ga空位周围的费米面显著高于正常GaN晶格的费米面.因此Ga空位周围N原子的处于费米面上的2p电子很易被激发成正常晶格处的传导电子 关键词: GaN 电子结构 团簇埋入自洽计算  相似文献   

6.
第一性原理对Ga_nN_n(n=2~5)小团簇的结构及电子性质的研究   总被引:1,自引:0,他引:1  
利用密度泛函理论的B3LYP方法在6-31G*的水平上对GanNn(n=2~5)团簇的结构进行优化,得到了GanNn(n=2~5)团簇的最稳定结构.并对最稳定结构的电子性质、成键特性和极化率进行分析.结果表明,团簇的最稳定结构为平面结构,且存在着N2和N3单元,说明N-N键在团簇的形成过程中起着决定性的作用;能隙间隔为1.776~3.563eV,表明GanNn(n=2~5)团簇已具有了半导体的性质.  相似文献   

7.
Ga_nN_3(n=1~8)团簇几何结构及光电子能谱的研究   总被引:2,自引:2,他引:0  
用密度泛函理论的B3LYP方法在6-31G*的水平上,对GanN3(n=1~8)团簇的结构进行优化,并对体系的成键特性、光电子能谱及稳定性进行了计算与分析,得到了GanN3(n=1~8)团簇的最稳定结构.结果表明,当n≤5时,其基态几何结构为平面结构,N-N键在这些团簇的形成过程中起着决定性的作用;当n≥6时,其基态几何结构为立体结构,Ga-N键起主导作用;在所研究的团簇中,Ga4N3、Ga7N3的基态结构最稳定;随着n值的增大,平均极化率逐渐增强;通过对光电子能谱的分析,得到Ga-N键的振动频率与六方晶系纤锌矿结构GaN的光学声子峰值相近.  相似文献   

8.
第一性原理对GanPm小团簇的结构及稳定性的研究   总被引:2,自引:0,他引:2       下载免费PDF全文
利用密度泛函理论(DFT)对GanP和GanP2 (n=1-7)团簇的几何结构、电子态及稳定性进行了研究. 在B3LYP/6-31G*水平上进行了结构优化和频率分析,得到了GanP和GanP2(n=1-7) 团簇的基态结构. 结果表明,n≤5团簇的几何结构基本上为平面结构,n>5的团簇均为立体结构;在GanP2 (n=1-6)团簇中,P-P比Ga-P容易成键;在GanP和GanP2 (n=1-7) 团簇中,Ga3P, Ga4P, GaP2, Ga2P2 和 Ga4P2的基态结构最稳定,在所研究的团簇中,稳定性随团簇总原子数的增大而减小.  相似文献   

9.
GanN-m阴离子团簇的结构及稳定性的研究   总被引:2,自引:0,他引:2       下载免费PDF全文
利用密度泛函理论(DFT)对GanN-(n=2-8)和GanN2-(n=1-7)阴离子团簇的结构及稳定性进行了研究.在B3LYP/6-31G*水平上进行了结构优化和频率分析,得到了GanN-(n=2-8)和GanN2-(n=1-7)阴离子团簇的基态结构.在这些团簇中,原子总数小于等于6的团簇的几何结构为平面结构,原子总数大于6的团簇的几何结构为立体结构;在所研究的团簇中,Ga4N-,Ga6N-,Ga4N-2和Ga5N-2的基态结构较稳定.  相似文献   

10.
利用密度泛函理论B3LYP方法, 在6-311G*基组水平上对(KN3)n(n=1~5)团簇各种可能的结构进行了几何结构优化, 预测了各团簇的最稳定结构. 并对最稳定结构的振动特性、成键特性、电荷分布和稳定性性质进行了分析研究. 结果表明, 叠氮化合物中叠氮基以直线型存在, KN3团簇最稳定结构为直线型, (KN3)n(n=2~3)团簇最稳定结构为环形结构, (KN3)n(n=4~5)团簇最稳定结构是由(KN3)2团簇最稳定结构形成的平面和空间结构. N-N 键键长在0.1156~0.1196 nm之间, N-K键键长在0.2357~0.2927 nm之间; 叠氮基中间的N原子显示正电性, 两端的N原子显示负电性, 且与K原子直接作用的N原子负电性更强, 金属K原子与N原子之间形成离子键. (KN3)n(n=1~5)团簇最稳定结构的IR光谱最强振动峰均位于2180~2230 cm-1, 振动模式为叠氮基中N-N键的反对称伸缩振动. 稳定性分析显示, (KN3)3团簇具有相对较高的动力学稳定性.  相似文献   

11.
张材荣  陈宏善  宋燕  许广济 《中国物理》2007,16(8):2394-2399
In this paper, possible structures of GasP5 cluster were optimized by using density functional method with generalized gradient correction (B3LYP). The electronic structure of the isomers with lower energy was studied. The most stable structure obtained for GasP5 is a distorted pentaprism. The Ga-P bond formed in the cluster is strongly ionic. Based on NBO analysis, an average value of 0.59 electron transfers from Gallium to Phosphorus. The bond length 2.33-2.43 is around the value in bulk GaP. The HOMO-LUMO gap is about 2.2 eV. The dipole moment and polarizability are calculated, and the IR and Raman spectra are also presented.  相似文献   

12.
Ga6N6团簇结构性质的理论计算研究   总被引:5,自引:0,他引:5       下载免费PDF全文
郝静安  郑浩平 《物理学报》2004,53(4):1044-1049
在密度泛函理论的基础上,对Ga6N6团簇进行了第一性原理、全电子、从头计算,得到了10种可能的三维空间结构及其电子结构.其中最稳定结构的一对GaN原子的平均结合能为9.748 eV,因此是可能存在的.但与他人计算的Ga3N3和Ga5N5相比,Ga6N6团簇可能不属于“幻数”团簇.最稳定结构的Ga6N6 关键词: GaN 团簇 电子结构  相似文献   

13.
杨建宋  李宝兴 《中国物理 B》2010,19(9):97103-097103
This paper investigates the structures and stabilities of neutral Ga7As7 cluster and its ions in detail by using first-principles density functional theory. Many low energy structures of Ga7As7 cluster are found. It confirms that the ground state structure of neutral Ga7As7 cluster is a pentagonal prism with four face atoms like a basket structure, as reported by previous works. The ground state structures of positive Ga7As7 cluster ions are different from that of the neutral cluster. These investigations suggest that Ga atoms occupy the capping positions more easily than As atoms. Mulliken population analyses also show that Ga atoms can lose or obtain charge more easily than As atoms. It finds that the neutral Ga7As7 cluster can become more stable by gaining one or two additional electrons but further more electrons would cause the decrease of binding energy. The ionisation energy increases with the increase of the number of the removed electrons. These calculated results indicate that the net magnetic moment of the neutral Ga7As7 cluster is zero because all electrons are paired together in their respective molecular orbits. But for the ionic Ga7As7 cluster with odd number of electrons, the net magnetic moment is 1.0 μB due to an unpaired electron.  相似文献   

14.
李萍  熊勇  芶清泉  张建平 《中国物理》2002,11(10):1018-1021
We propose the formation mechanism of the body-centred regular tetrahedral structure of the He5^ cluster,The total energy curve for this structure has been calculated by using a modified arrangement channel quantum mechanics method.The result shows that a minimal energy of -13.9106 a.u.occurs at a separation of 1.14a0 between the nucleus at the centre and nuclei at the apexes.Therefore we obtain the binding energy of 0.5202a .u.for this structure.This means that the He5^ cluster may be stable with a high binding energy in a body-centred regular tetrahedral structure.  相似文献   

15.
贾文红  武海顺 《物理学报》2004,53(4):1056-1062
采用密度泛函理论中B3LYP泛函方法,在6—31G*水平上,对GamPn(m+n≤5)团簇及其阴离子的几何构型和振动光谱性质进行了研究. 在相同水平下计算了GamP-n(m+n≤5)的垂直电离能和GamPn(m+n≤5)的绝热电子亲核势. 结果表明:单线态稳定结构有较高的对称性,二重态的稳定结构对称性相对较低. 关键词: mPn和GamP-n团簇')" href="#">GamPn和GamP-n团簇 密度泛函理论 光电子能谱  相似文献   

16.
龚恒风  李公平  贾艳辉 《中国物理 B》2011,20(3):33105-033105
In this work,a systematic study of some possible isomer structures of the Cu 5 cluster obtained from density functional theory methods is presented.The polarisation and pseudopotential basis sets are employed in the calculations.The results show that the binding energies,frequencies,coordination numbers and average bond lengths are in reasonable agreement with reported experimental data.Moreover,four isomers of the Cu 5 cluster are obtained according to calculations,in which the most stable configuration is the planar structure.Meanwhile,two three-dimensional structures of the Cu 5 cluster are obtained in this work,which might be valuable for further theoretical and experimental studies.In addition,our study proves the possibility of the isomer structures of the Cu 5 cluster.  相似文献   

17.
利用密度泛函理论通过计算吸附能量、HOMO/LUMO能隙变化、电荷转移、结构扭曲等研究二氧化氮分子在B12N12纳米笼的吸附.此外,通过计算B12N12的电子结合能、Gibbs自由能、态密度和分子表面的静电势研究其稳定性和其它特性.B12N12纳米笼吸附二氧化氮显示三种构型.B12N12团簇的HOMO/LUMO能隙变化对二氧化氮分子的存在非常敏感,从自由团簇的6.84 eV降为NO2/团簇稳定团簇的3.23 eV.团簇的导电性被极大地提高,表明B12N12纳米簇可能是潜在的二氧化氮气体分子检测传感器.  相似文献   

18.
The host Gan+1 and doped GanNb (n=1-9) clusters with several spin configurations have been systematically investigated by a relativistic density functional theory (DFT) with the generalized gradient approximation. The optimized equilibrium geometries tend to prefer the close-packed configurations for small Nb-doped gallium clusters up to n=9. The average binding energies per atom (Eb/atom), second-order differences of total energies (Δ2E), fragmentation energies (Ef) and HOMO-LUMO gaps of Gan+1 and GanNb (n=1-9) clusters are studied. The results indicate the doping of Nb atom in gallium clusters improves the chemical activities. In particular, the clusters with sizes of Ga4Nb and Ga7Nb are found to be more stable with respect to their respective neighbors. Our calculated vertical ionization potentials (VIPs) exhibit an obvious oscillating behavior with the cluster size increasing, except for Ga3 and Ga4Nb, suggesting the Ga3, Ga5, Ga7, GaNb, Ga3Nb, Ga6Nb and Ga8Nb clusters corresponding to the high VIPs. In the case of vertical electron affinities (VEAs) and chemical hardness η, VEAs are slightly increasing whereas chemical hardness η decreasing as GanNb cluster size increases. Besides, the doping of Nb atom also brings the decrease as the cluster sizes increases for atomic spin magnetic moments (μb).  相似文献   

19.
The structural, electronic and magnetic properties of small gallium clusters doped with Cobalt have been studied using spin-polarised density functional theory. The binding energy per atom, second-order differences of total energies and fragmentation energies of equilibrium geometries of the host Gan+1 and doped GanCo (n = 1–12) clusters are computed. Doped clusters are found to be more stable than pure Ga clusters; Ga3Co, Ga5Co and Ga8Co clusters are exceptionally stable. Doping with Co changes the highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO–LUMO) gap, and also affects the magnetic moments of clusters.  相似文献   

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