Relativistic Effects in Chemical Systems

Christiansen, P. A.; Ermler, Walter C.; Pitzer, Kenneth S.

doi:10.1146/annurev.pc.36.100185.002203

Cited by 221 publications

(69 citation statements)

References 17 publications

(18 reference statements)

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“…The Swart-Solá-Bickelhaupt (SSB-D) functional 53,54 , was constructed on the basis of a small correction of the PBE functional, together with Grimme's dispersion correction and it was shown to work well for spin states of transition metal complexes, S N 2 reaction barriers, accuracy of geometries, hydrogen bonding, and π − π stacking interactions. One of the most important factors for a correct description of heavy transition metals such as Pt is undoubtedly relativistic effects [55][56][57][58] . An accurate way to include relativistic effects is to use the full four-component Dirac equation 59 , however the application of such approaches is still considerably time-consuming and not suitable for applications like the interaction between Pt clusters and carbon surfaces.…”

Section: Introductionmentioning

confidence: 99%

Structural and electronic properties of the Pt_n–PAH complex (n = 1, 2) from density functional calculations

Mahmoodinia

Ebadi

Åstrand

et al. 2014

Phys. Chem. Chem. Phys.

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A detailed density functional study of the Pt atom and Pt dimer adsorption on a polyaromatic hydrocarbon (PAH) is presented. The preferred adsorption site for a Pt atom is confirmed to be the bridge site. Upon adsorption of a single Pt atom, however, it is found here that the electronic ground state changes from the triplet state (5d 9 6s 1 configuration) to the closed-shell singlet state (5d 10 6s 0 configuration), which consequently will affect the catalytic activity of Pt when single Pt atoms bind to a carbon surface. The preferred adsorption site for the Pt dimer in the upright configuration is the hollow site. In contrast to the adsorption of a single Pt atom, the formation of a Pt-C bond in the adsorption of a Pt dimer is not accompanied by a change in the spin state, so the most stable electronic state is still the triplet state. While the atomic charge on the Pt atoms and dimers (in parallel configuration) in the Pt n /PAH complex is positive, a negative charge is found on the upper Pt atom for the upright configuration, indicating that single layers of Pt atoms will have a different catalytic activity as compared to Pt clusters on a carbon surface. Comparing the Pt-C bond length and the charge transfer on different sites, the magnitude of the charge transfer decreases with bond elongation, indicating that the catalytic activity of the Pt atom and dimer can be changed by modifying its chemical surroundings. The adsorption energy for the Pt dimer on a PAH surface is larger than for two individual Pt atoms on the surface indicating that aggregation of Pt atoms on the PAH surface is favorable.

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Section: Introductionmentioning

confidence: 99%

Structural and electronic properties of the Pt_n–PAH complex (n = 1, 2) from density functional calculations

Mahmoodinia

Ebadi

Åstrand

et al. 2014

Phys. Chem. Chem. Phys.

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“…One such direction is the inclusion of spin-orbit interactions in Hamiltonian. The importance of relativity for the description of heavy elements is well recognized, [1][2][3] and the spinorbit interaction is present in the relativistic formalism based upon Dirac operator for the electron. Spin-orbit and other relativistic effects required for the accurate description of valence states of molecules containing heavy elements can be represented as two-component relativistic effective core potentials (RECPs) derived from Dirac-Coulomb Hamiltonian based all-electron calculations of atoms.…”

Section: Introductionmentioning

confidence: 99%

Spin-orbit Effects on the Structure of Haloiodomethane Cations CH₂XI⁺(X=F, Cl, Br, and I)

Kim¹,

Park²,

Lee³

2014

Bulletin of the Korean Chemical Society

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The importance of including spin-orbit interactions for the correct description of structures and vibrational frequencies of haloiodomethanes is demonstrated by density functional theory calculations with spin-orbit relativistic effective core potentials (SO-DFT). The vibrational frequencies and the molecular geometries obtained by SO-DFT calculations do not match with the experimental results as well as for other cations without significant relativistic effects. In this sense, the present data can be considered as a guideline in the development of the relativistic quantum chemical methods. The influence of spin-orbit effects on the bending frequency of the cation could well be recognized by comparing the experimental and calculated results for CH 2 BrI and CH 2 ClI cations. Spin-orbit effects on the geometries and vibrational frequencies of CH 2 XI (X=F, Cl, Br, and I) neutral are negligible except that C-I bond lengths of haloiodomethane neutral is slightly increased by the inclusion of spin-orbit effects. The A'' states were found in the cations of haloiodomethanes and mix due to the spin-orbit interactions and generate two 2 E 1/2 fine-structure states. The geometries of CH 2 XI + (X=F and Cl) from SO-DFT calculations are roughly in the middle of two cation geometries from DFT calculations since two cation states of CH 2 XI (X=F and Cl) from DFT calculations are energetically close enough to mix two cation states. The geometries of CH 2 XI + (X=Br and I) from SO-DFT calculations are close to that of the most stable cation from DFT calculations since two cation states of CH 2 XI (X=Br and I) from DFT calculations are energetically well separated near the fine-structure state minimum.

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“…This effort can be reduced by using pseudopotentials I- [1][2][3][4][5]. Only the valence electrons are treated explicitly, while the core is represented by a pseudopotential.…”

Section: Introductionmentioning

confidence: 99%

“…Instead of the adjustment to orbital energies and orbital densities [8][9][10][11][12][13], the pseudopotentials used in this work [14] are fitted to experimental ionization and excitation energies of one-valence electron atoms [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. This treatment implicitly includes relativistic effects.…”

Section: Introductionmentioning

confidence: 99%

Comparative study of spectroscopic properties of some indium, tin and antimony compounds

et al. 1989

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Relativistic Effects in Chemical Systems

Cited by 221 publications

References 17 publications

Structural and electronic properties of the Pt_n–PAH complex (n = 1, 2) from density functional calculations

Structural and electronic properties of the Pt_n–PAH complex (n = 1, 2) from density functional calculations

Spin-orbit Effects on the Structure of Haloiodomethane Cations CH₂XI⁺(X=F, Cl, Br, and I)

Comparative study of spectroscopic properties of some indium, tin and antimony compounds

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Relativistic Effects in Chemical Systems

Cited by 221 publications

References 17 publications

Structural and electronic properties of the Ptn–PAH complex (n = 1, 2) from density functional calculations

Structural and electronic properties of the Ptn–PAH complex (n = 1, 2) from density functional calculations

Spin-orbit Effects on the Structure of Haloiodomethane Cations CH2XI+(X=F, Cl, Br, and I)

Comparative study of spectroscopic properties of some indium, tin and antimony compounds

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Product

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About

Structural and electronic properties of the Pt_n–PAH complex (n = 1, 2) from density functional calculations

Structural and electronic properties of the Pt_n–PAH complex (n = 1, 2) from density functional calculations

Spin-orbit Effects on the Structure of Haloiodomethane Cations CH₂XI⁺(X=F, Cl, Br, and I)