1
|
Tosoni S, Pacchioni G. Magnetic nature and hyperfine interactions of transition metal atoms adsorbed on ultrathin insulating films: a challenge for DFT. Phys Chem Chem Phys 2022; 24:15891-15903. [PMID: 35762384 DOI: 10.1039/d2cp01224c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The magnetic ground state and the hyperfine coupling parameters of some first-row transition metal (TM) atoms (Ti, Cr, Mn, Fe, Co, and Ni) adsorbed on ultrathin insulating oxide films are studied by means of DFT calculations. The results obtained using GGA, screened hybrid, and GGA+U functionals are compared for TMs adsorbed on free-standing MgO(100). Then, the case of adsorption on MgO mono- and bilayers supported on Ag(100) is studied using GGA+U. Along with the problematic aspects inherent to the calculation of hyperfine coupling constants, a critical dependence on the magnetic state and electron configuration of the TM is reported, which implies a real challenge for the state-of-the-art DFT methods. In the cases where all functionals considered provide a coherent magnetic and electron configuration, however, the calculated hyperfine parameters do not depend significantly on the choice of the functional. In this respect, the role of the metal support in the hyperfine coupling constants is highly system-dependent and becomes crucial in all cases where the support modifies the oxidation state of the adatom, induces a change in the bonding site or simply induces a rearrangement of the orbital energy diagram. This has important implications for the modelling of single TM atoms deposited on insulating ultrathin films supported on metals for application in quantum technologies or as memory devices.
Collapse
Affiliation(s)
- Sergio Tosoni
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Via Roberto Cozzi 55, 20125 Milan, Italy.
| | - Gianfranco Pacchioni
- Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Via Roberto Cozzi 55, 20125 Milan, Italy.
| |
Collapse
|
2
|
Kou YY, Zhao Q, Wang XR, Li ML, Ren XH. Synthesis of three new binuclear Mn complexes: characterization and DNA binding and cleavage properties. J COORD CHEM 2019. [DOI: 10.1080/00958972.2019.1647339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Ying-Ying Kou
- Key Laboratory of Urban Stormwater System and Water Environment, Beijing University of Civil Engineering and Architecture, Beijing, P. R. China
| | - Qian Zhao
- Key Laboratory of Urban Stormwater System and Water Environment, Beijing University of Civil Engineering and Architecture, Beijing, P. R. China
| | - Xue-Rao Wang
- Key Laboratory of Urban Stormwater System and Water Environment, Beijing University of Civil Engineering and Architecture, Beijing, P. R. China
| | - Mei-Ling Li
- Key Laboratory of Urban Stormwater System and Water Environment, Beijing University of Civil Engineering and Architecture, Beijing, P. R. China
| | - Xiang-Hao Ren
- Key Laboratory of Urban Stormwater System and Water Environment, Beijing University of Civil Engineering and Architecture, Beijing, P. R. China
| |
Collapse
|
3
|
|
4
|
Helali Z, Markovits A, Minot C, Abderrabba M. Metal atom adsorption on a defective TiO2–x support. Chem Phys Lett 2014. [DOI: 10.1016/j.cplett.2014.01.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
5
|
Sousa C, Tosoni S, Illas F. Theoretical Approaches to Excited-State-Related Phenomena in Oxide Surfaces. Chem Rev 2012. [DOI: 10.1021/cr300228z] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Carmen Sousa
- Departament de Química
Física and Institut de Química Teòrica i Computacional
(IQTCUB), Universitat de Barcelona, C/Martí
i Franquès 1, 08028 Barcelona, Spain
| | - Sergio Tosoni
- Departament de Química
Física and Institut de Química Teòrica i Computacional
(IQTCUB), Universitat de Barcelona, C/Martí
i Franquès 1, 08028 Barcelona, Spain
- Departamento de Química, Universidad de Las Palmas de Gran Canaria, Campus Universitario
de Tafira, 35017 Las Palmas de Gran Canaria, Spain
| | - Francesc Illas
- Departament de Química
Física and Institut de Química Teòrica i Computacional
(IQTCUB), Universitat de Barcelona, C/Martí
i Franquès 1, 08028 Barcelona, Spain
| |
Collapse
|
6
|
Adsorption and spin state properties of Cr, Ni, Mo, and Pt deposited on Li+ and Na+ monovalent cation impurities of MgO (001) surface: DFT calculations. J Mol Model 2011; 17:3299-308. [DOI: 10.1007/s00894-011-1017-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Accepted: 02/09/2011] [Indexed: 10/18/2022]
|
7
|
Rong C, Lian S, Yin D, Shen B, Zhong A, Bartolotti L, Liu S. Towards understanding performance differences between approximate density functionals for spin states of iron complexes. J Chem Phys 2006; 125:174102. [PMID: 17100424 DOI: 10.1063/1.2378830] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Density functional theory has been widely used to investigate the structural and electronic properties of heme-containing proteins such as cytochrome P450. Nevertheless, recent studies have shown that approximate exchange-correlation energy density functionals can incorrectly predict the stability order of spin states in, for instance, iron-containing pyridine and imidazole systems. This raises questions about the validity of earlier theoretical studies. In this work, we systematically investigate a few typical inorganic and organic iron-containing complexes and try to understand the performance difference of various density functionals. Two oxidation states of iron, Fe(II) and Fe(III), with different spin states and both adiabatic and vertical structures are considered. A different description of the outmost molecular orbital is found to play the crucial role. Local density and generalized gradient based functionals bias the lower spin state and produce a more localized frontier orbital that is higher in energy than the hybrid functionals. Energy component analysis has been performed, together with comparison of numerous structural and electronic properties. Implications of the present work to the theoretical study of heme-containing biological molecules and other spin-related systems are discussed.
Collapse
Affiliation(s)
- Chunying Rong
- College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
8
|
Neyman KM, Inntam C, Matveev AV, Nasluzov VA, Rösch N. Single d-Metal Atoms on Fs and Fs+ Defects of MgO(001): A Theoretical Study across the Periodic Table. J Am Chem Soc 2005; 127:11652-60. [PMID: 16104741 DOI: 10.1021/ja052437i] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Single d-metal atoms on oxygen defects F(s) and F(s+) of the MgO(001) surface were studied theoretically. We employed an accurate density functional method combined with cluster models, embedded in an elastic polarizable environment, and we applied two gradient-corrected exchange-correlation functionals. In this way, we quantified how 17 metal atoms from groups 6-11 of the periodic table (Cu, Ag, Au; Ni, Pd, Pt; Co, Rh, Ir; Fe, Ru, Os; Mn, Re; and Cr, Mo, W) interact with terrace sites of MgO. We found bonding with F(s) and F(s+) defects to be in general stronger than that with O2- sites, except for Mn-, Re-, and Fe/F(s) complexes. In M/F(s) systems, electron density is accumulated on the metal center in a notable fashion. The binding energy on both kinds of O defects increases from 3d- to 4d- to 5d-atoms of a given group, at variance with the binding energy trend established earlier for the M/O2- complexes, 4d < 3d < 5d. Regarding the evolution of the binding energy along a period, group 7 atoms are slightly destabilized compared to their group 6 congeners in both the F(s) and F(s+) complexes; for later transition elements, the binding energy increases gradually up to group 10 and finally decreases again in group 11, most strongly on the F(s) site. This trend is governed by the negative charge on the adsorbed atoms. We discuss implications for an experimental detection of metal atoms on oxide supports based on computed core-level energies.
Collapse
|
9
|
Viñes F, Sousa C, Liu P, Rodriguez JA, Illas F. A systematic density functional theory study of the electronic structure of bulk and (001) surface of transition-metals carbides. J Chem Phys 2005; 122:174709. [PMID: 15910062 DOI: 10.1063/1.1888370] [Citation(s) in RCA: 161] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A systematic study of the bulk and surface geometrical and electronic properties of a series of transition-metal carbides (TMC with TM = Ti, V, Zr, Nb, Mo, Hf, Ta, and W) by first-principles methods is presented. It is shown that in these materials the chemical bonding is strongly covalent, the cohesive energies being directly related to the bonding-antibonding gap although the shift of the center of the C(2s) band related peak in the density of states with respect to diamond indicates that some metal to carbon charge transfer does also take place. The (001) face of these metal carbides exhibits a noticeable surface rumpling which grows along the series. It is shown that neglecting surface relaxation results in very large errors on the surface energy and work function. The surface formation induces a significant shift of electronic energy levels with respect to the corresponding values in the bulk. The extent and nature of the shift can be understood from simple bonding-antibonding arguments and is enhanced by the structural rippling of this surface.
Collapse
Affiliation(s)
- F Viñes
- Departament de Química Física & Centre especial de Recerca en Química Teòrica, Universitat de Barcelona & Parc Científic de Barcelona, Spain
| | | | | | | | | |
Collapse
|
10
|
Xu YJ, Li JQ, Zhang YF, Chen WK. The adsorption and dissociation of Cl2 on the MgO (001) surface with vacancies: Embedded cluster model study. J Chem Phys 2004; 120:8753-60. [PMID: 15267807 DOI: 10.1063/1.1697375] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The adsorption of Cl(2) at a low-coordinated oxygen site (edge or corner site) and vacancy site (terrace, edge, corner F, F(+), or F(2+) center) has been studied by the density functional method, in conjunction with the embedded cluster models. First, we have studied the adsorption of Cl(2) at the edge and corner oxygen sites and the results show that Cl(2), energetically, is inclined to adsorb at the corner oxygen site. Moreover, similar to the most advantageous adsorption mode for Cl(2) on the MgO (001) perfect surface, the most favorable adsorption occurs when Cl(2) approaches the corner oxygen site along the normal direction. A small amount of electrons are transferred from the substrate to the antibonding orbital of the adsorbate, leading to the Cl-Cl bond strength weakened a little. Regarding Cl(2) adsorption at the oxygen vacancy site (F, F(+), or F(2+) center), both large adsorption energies and rather much elongation of the Cl-Cl bond length have been obtained, in particular at the corner oxygen vacancy site, with concurrently large amounts of electrons transferred from the substrate to the antibonding orbital of Cl(2). It suggests, at the oxygen vacancy site, that Cl(2) prefers to dissociate into Cl subspecies. And the potential energy surface indicates that the dissociation process of molecular Cl(2) to atomic Cl is virtually barrierless.
Collapse
Affiliation(s)
- Yi-Jun Xu
- Department of Chemistry, Fuzhou University, Fuzhou, 350002,
| | | | | | | |
Collapse
|
11
|
Brazzelli S, Di Valentin C, Pacchioni G, Giamello E, Chiesa M. Alkali Metal Doping of MgO: Mechanisms of Formation of Paramagnetic Surface Centers. J Phys Chem B 2003. [DOI: 10.1021/jp0341321] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|