Structure and electronic properties of GaN tubelike clusters and single-walled GaN nanotubes

2015 ◽  
Vol 29 (17) ◽  
pp. 1550116 ◽  
Author(s):  
Liren Liu ◽  
Yanbo Zou ◽  
Hengjiang Zhu

Extensive studies of the geometric structures, stabilities and electronic properties of gallium nitride (GaN)n tubelike clusters and single-walled GaN nanotubes (GaNNTs) were carried out using density-functional theory (DFT) calculations. A family of stable tubelike structures with Ga–N alternating arrangement was observed when n≥8 and their structural units (four-membered rings (4MRs) and six-membered rings (6MRs)) obey the general developing formula. The size-dependent properties of the frontier molecular orbital surfaces explain why the long and stable tubelike clusters can be obtained successfully. They also illustrate the reason why GaNNTs can be synthesized experimentally. Our results also reveal that the single-walled GaNNTs, which as semiconductors with a large bandgap, can be prepared by using the proper assembly of tubelike clusters.

2021 ◽  
pp. 1-8
Author(s):  
Azadeh Jafari Rad ◽  
Maryam Abbasi ◽  
Bahareh Zohrevand

This work was performed regarding the importance of iron (Fe) chelation for biological systems. This goal was investigated by assistance of a model of thiocytosine (TC) for participating in Fe-chelation processes. First, formations of tautomeric conformations were investigated to explore existence of possible structures of TC. Next, Fe-chelation processes were examined for all four obtained tautomers of TC. The results indicated that thiol tautomers could be seen at higher stability than thio tautomers, in which one of such thiol tautomers yielded the strongest Fe-chelation process to build FeTC3 model. As a consequence, parallel to the results of original TC tautomers, Fe-chelated models were found to be achievable for meaningful chelation processes or sensing the existence of Fe in media. Examining molecular orbital features could help for sensing purposes. The results of this work were obtained by performing density functional theory (DFT) calculations proposing TC compounds suitable for Fe-chelation purposes.


2020 ◽  
Vol 44 (34) ◽  
pp. 14513-14528
Author(s):  
Alireza Soltani ◽  
Mohammad Ramezanitaghartapeh ◽  
Masoud Bezi Javan ◽  
Mohammad T. Baei ◽  
Andrew Ng Kay Lup ◽  
...  

The interaction energies and optoelectronic properties of sarin (SF) and chlorosarin (SC) on the B12N12 with and without the presence of an electric field have been studied using density functional theory (DFT) calculations.


2021 ◽  
Vol 2063 (1) ◽  
pp. 012002
Author(s):  
Dalal H Alsawad ◽  
Ali A Al-Riyahee ◽  
Ali J Hameed

Abstract A series of 4-(para-substituted phenyl)-1,2,3-selenadiazole adducts of [VO(acac)2] were studied by density functional theory (DFT) calculations. The 4-(para-substituted phenyl)-1,2,3-selenadiazole molecules have been selected to be bound with vanadium atom in [VO(acac)2] through Se, N2 and N3. The resulting adducts have been investigated in two geometries (cis and trans) in order to show the effect of such structural change on the electronic properties of the studied adducts. The optimized geometries, (binding and reorganization) energies and the spatial distribution of the highest molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the adducts are presented and discussed.


2020 ◽  
Vol 34 (32) ◽  
pp. 2050359
Author(s):  
Yi Zhang ◽  
Weiwei Ju ◽  
Tongwei Li ◽  
Haisheng Li

By performing density functional theory (DFT) calculations, we demonstrate that periodically repeating heterostructures of zigzag borophene nanoribbons (BNR) of different widths can form stable borophene superlattice (BSL). The energy band structures of BSL can be modulated through modifying the width and length of the segments. A metal-semiconductor transition can be obtained when the length of each segment is lengthened, whereas, the magnetism of BSL is influenced by the width of the segments. In those magnetic systems, the magnetic moments are mainly localized on protruding B atoms located at the edge, while no magnetic moments occur in the center B atoms. The hydrogenated BNR and BSL are further investigated. The hydrogenation can modify the electronic properties of BNR and BSL as well as quench the magnetism. All hydrogenated BNR and BSL are non-magnetic. Our results indicate that great potential exists in these systems for borophene utilization in nanoelectronics and spintronics.


RSC Advances ◽  
2020 ◽  
Vol 10 (15) ◽  
pp. 8927-8935 ◽  
Author(s):  
Douglas Duarte de Vargas ◽  
Rogério José Baierle

Using density functional theory (DFT) calculations we investigate the structural and electronic properties of a heterogeneous van der Waals (vdW) structure consisting of silicene and NiI2 single layers.


2021 ◽  
pp. 1-10
Author(s):  
Mohammad Javed Ansari ◽  
Gunawan Widjaja ◽  
Wanich Suksatan ◽  
Usama S. Altimari ◽  
Ahmed Kareem Abd ALhusain

A model of OC20 fullerene-oxide (FO) was investigated in this work for adsorbing the ammonia (NH3) substance by the hypothesis of formations of bimolecular complexes of the two substances. To affirm such hypothesis, the models of singular NH3 and FO were optimized to reach the minimized energy structures and all possibilities of their interactions configurations were examined. As a consequence, three NH3@FO bimolecular complex models were obtained for reaching the point of complex formations. Details of interactions indicated both direct and indirect contributions of the oxidized region of FO to interactions with both H and N atomic sites of NH3. In this regard, CPLX3 with two types of H. . . O and N. . . C interactions was seen to be at the highest strength of adsorption and complex formation in comparison with CPLX1 and CPLX2 models including only one interaction of each of H. . . O and N. . . C type, respectively. Moreover, the obtained electronic molecular orbital features revealed the sensor function of FO material versus the NH3 substance. As a consequence, the hypothesis of NH3@FO complexes formation was affirmed with two proposed functions of removal and detection for the investigated FO material. All results of this work were obtained by details through performing density functional theory (DFT) calculations.


Author(s):  
YAMIN WU ◽  
BIN LIAO ◽  
GUOLIANG WANG ◽  
BAOAN Bian

The effect of asymmetric lateral linking groups on the electronic transport is investigated in the biphenyl molecule-based device with gold electrodes with the framework of density functional theory and nonequilibrium Green’s function. The asymmetric lateral linking groups reduce the currents of molecular junctions, and result in the reverse rectifying behavior. The devices with asymmetric lateral linking groups –SH and –SCH3 have maximum rectifying ratios, while the asymmetric lateral linking group –SH and –NH2 cause minimum rectifying ratios. The calculated results suggest that the asymmetric lateral linking group induces the reduced coupling between molecule and right electrode, asymmetric distribution of frontier molecular orbital and asymmetric evolution of the molecular orbital eigenenergies, accounting for the rectifying behavior.


2003 ◽  
Vol 2003 (7) ◽  
pp. 384-385 ◽  
Author(s):  
Davood Nori-Shargh ◽  
Nasrin Sarogh-Farahani ◽  
Saeed Jameh-Bozorghi ◽  
Farzad Deyhimi ◽  
Mohammad-Reza Talei Bavil Olyai ◽  
...  

Ab initio molecular orbital and density functional theory (DFT) calculations, used to calculate the structure optimisation and configurational features of cyclodeca-1,2,4,6,7,9-hexaene (1) and cyclodeca-1,2,4,6,8,9-hexaene (2), showed that the important structures in compound 1 are: RZRZ ( D2 symmetry), RZSZ ( C2h symmetry) and for compound 2 are: RSZZ ( C1 symmetry), RRZZ ( C2 symmetry).


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