1
|
Ab initio DFT simulation of electronic and magnetic properties of Ti n+1 and FeTi n clusters. J Mol Model 2022; 28:56. [PMID: 35132467 DOI: 10.1007/s00894-022-05041-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/24/2022] [Indexed: 10/19/2022]
Abstract
We report a computational investigation of the electronic and magnetic properties of neutral Tin+1 and FeTin (n = 1-10) clusters using ab initio calculations based on density functional theory (DFT) within the generalized gradient approximation (GGA). The best structures for Tin+1 and FeTin clusters are planar for size n < 5, while from n = 5, they showed a compact three-dimensional cage structure. For the best structures of the FeTin clusters, the Fe atoms favor the peripheral position with the highest coordination with the neighboring Ti atoms. The evolution as a function of the size of the average binding energies (Eb/atom) and HOMO-LUMO gaps of Tin+1 and FeTin (n = 1-10) clusters are studied. The stability results show that the Tin+1 clusters have relatively higher stability than the FeTin cluster with the same size. In addition, the vertical ionization potentials and electron affinities, chemical hardness, and atomic magnetic moment of Tin+1 and FeTin (n = 1-10) clusters are also investigated.
Collapse
|
2
|
Gilmour JTA, Gaston N. On the influence of exact exchange on transition metal superatoms. Phys Chem Chem Phys 2020; 22:772-780. [PMID: 31833486 DOI: 10.1039/c9cp04229f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The electronic structure of A7C (A = Hg, Pd, V, Cr, Mn, Fe, Ni, Cu; C = 0, ±1, ±2) clusters has been determined using density functional theory methods. The A7C (A = Hg, Pd, Cr, Cu; C = 0, ±1, ±2) clusters all conform to the existing superatomic model, with a sufficiently stabilised local structure to prevent perturbation upon the introduction of exact exchange to the exchange correlation functional. For the A7C (A = Mn, Fe, Ni; C = 0, ±1, ±2) clusters the incorporation of exact exchange separates the atomic s- and d-electrons, leading to a net increase in the number of superatomic electrons. Conversely the incorporation of exact exchange into the exchange correlation functional decreases the number of superatomic electrons for the V7C (C = 0, ±1, ±2) clusters, owing to the radial extension of the d-orbitals influencing their ability to contribute into superatomic shells.
Collapse
Affiliation(s)
- J T A Gilmour
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, The Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| | | |
Collapse
|
3
|
Gilmour JTA, Gaston N. On the involvement of d-electrons in superatomic shells: the group 3 and 4 transition metals. Phys Chem Chem Phys 2019; 21:8035-8045. [PMID: 30932111 DOI: 10.1039/c9cp00323a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The geometries and electronic structures of small M7C (M = Sc, Y, La, Ti, Zr, Hf; C = 0, ±1, ±2) clusters have been calculated at a range of multiplicities at each cluster charge, using density functional theory methods. These clusters conform to the existing superatom model, with some contextual differences. There are a range of states which are populated by the outermost s and d-electrons of the constituent atoms, with an irregular Aufbau rule for the states formed from the atomic d-electrons. The states comprised of d-electrons present themselves as two states of P-symmetry and two states of F-symmetry, which are nearly degenerate, followed by states of D-symmetry, a shell ordering which arises due to the symmetry, and favourable overlap, of the contributing states. The effect of exact exchange in modulating the localisation of these states is also discussed. In addition, this study shows pseudo-superatomic states which arise due to the 5-fold symmetry of the clusters, materialising as either a ring or plane of electron density. In summary, these observations allow for an expansion of the role that early transition metals have within the existing superatom framework.
Collapse
Affiliation(s)
- J T A Gilmour
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, The Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| | - N Gaston
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, The Department of Physics, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| |
Collapse
|
4
|
Chikhaoui A, Ziane M, Tazibt S, Bouarab S, Vega A. Unveiling the effects of doping small nickel clusters with a sulfur impurity. Theor Chem Acc 2018. [DOI: 10.1007/s00214-018-2320-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
5
|
Jeon S, Kang DH, Lee YH, Lee S, Lee GW. Effect of atomic size on undercoolability of binary solid solution alloy liquids with Zr, Ti, and Hf using electrostatic levitation. J Chem Phys 2016; 145:174504. [PMID: 27825205 DOI: 10.1063/1.4966649] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigate the relationship between the excess volume and undercoolability of Zr-Ti and Zr-Hf alloy liquids by using electrostatic levitation. Unlike in the case of Zr-Hf alloy liquids in which sizes of the constituent atoms are matched, a remarkable increase of undercoolability and negative excess volumes are observed in Zr-Ti alloy liquids as a function of their compositional ratios. In this work, size mismatch entropies for the liquids were obtained by calculating their hard sphere diameters, number densities, and packing fractions. We also show that the size mismatch entropy, which arises from the differences in atomic sizes of the constituent elements, plays an important role in determining the stabilities of metallic liquids.
Collapse
Affiliation(s)
- S Jeon
- Frontier in Extreme Physics, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| | - D-H Kang
- Frontier in Extreme Physics, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| | - Y H Lee
- Frontier in Extreme Physics, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| | - S Lee
- Frontier in Extreme Physics, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| | - G W Lee
- Frontier in Extreme Physics, Korea Research Institute of Standards and Science, 267 Gajeong-ro, Yuseong-gu, Daejeon 34113, South Korea
| |
Collapse
|
6
|
Lee B, Lee GW. A liquid-liquid transition can exist in monatomic transition metals with a positive melting slope. Sci Rep 2016; 6:35564. [PMID: 27762334 PMCID: PMC5071854 DOI: 10.1038/srep35564] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 10/03/2016] [Indexed: 01/26/2023] Open
Abstract
Liquid-liquid transitions under high pressure are found in many elemental materials, but the transitions are known to be associated with either sp-valent materials or f-valent rare-earth elements, in which the maximum or a negative slope in the melting line is readily suggestive of the transition. Here we find a liquid-liquid transition with a positive melting slope in transition metal Ti from structural, electronic, and thermodynamic studies using ab-initio molecular dynamics calculations, showing diffusion anomaly, but no density anomaly. The origin of the transition in liquid Ti is a pressure-induced increase of local structures containing very short bonds with directionality in electronic configurations. This behavior appears to be characteristic of the early transition metals. In contrast, the late transition metal liquid Ni does not show the L-L transition with pressure. This result suggests that the possibility of the L-L transition decreases from early to late transition metals as electronic structures of late transition metals barely have a Jahn-Teller effect and bond directionality. Our results generalize that a phase transition in disordered materials is found with any valence band regardless of the sign of the melting slope, but related to the symmetry of electronic structures of constituent elements.
Collapse
Affiliation(s)
- Byeongchan Lee
- Kyung Hee University, 1732 Deogyeong-daero, Yongin, Gyeonggi 17104, Republic of Korea
| | - Geun Woo Lee
- Korea Research Institute of Standards and Science, Daejon 34113, Republic of Korea.,University of Science and Technology, Daejon 34113, Republic of Korea
| |
Collapse
|
7
|
Sun H, Ren Y, Wu Z, Xu N. Density functional calculation of the growth, electronic and bonding properties of titanium clusters Tin (n=2–20). COMPUT THEOR CHEM 2015. [DOI: 10.1016/j.comptc.2015.03.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
8
|
Fernando A, Weerawardene KLDM, Karimova NV, Aikens CM. Quantum Mechanical Studies of Large Metal, Metal Oxide, and Metal Chalcogenide Nanoparticles and Clusters. Chem Rev 2015; 115:6112-216. [PMID: 25898274 DOI: 10.1021/cr500506r] [Citation(s) in RCA: 217] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Amendra Fernando
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
| | | | - Natalia V Karimova
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
| | - Christine M Aikens
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
| |
Collapse
|
9
|
Gutsev GL, Weatherford CW, Belay KG, Ramachandran BR, Jena P. An all-electron density functional theory study of the structure and properties of the neutral and singly charged M12 and M13 clusters: M = Sc–Zn. J Chem Phys 2013; 138:164303. [DOI: 10.1063/1.4799917] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
|
10
|
Lee B, Lee GW. Local structure of liquid Ti: Ab initio molecular dynamics study. J Chem Phys 2008; 129:024711. [DOI: 10.1063/1.2953458] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|