Density functional study of manganese dimer

Yamanaka, Shusuke; Ukai, Tomofumi; Nakata, Kazuto; Takeda, Ryo; Kawakami, Takashi; Takada, Toshikazu; Yamaguchi, Kizashi

doi:10.1002/qua.21441

Cited by 22 publications

(29 citation statements)

References 81 publications

(105 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Assignment of the ground state of neutral Mn 2 dimer is challenging and is still under debate. The lowest total energy state of the dimer was found to possess the spin multiplicity of 11 if computed using density functional theory methods, [49][50][51] whereas Hartree-Fock based studies [52][53][54][55][56][57] have predicted a singlet 1 Σ g + state to be the ground state of Mn 2 . The latter is in agreement with an early experimental ESR study which predicted a singlet antiferromagnetic state for the dimer.…”

Section: Calibration Of Computational Methodsmentioning

confidence: 99%

Photoelectron spectra and structure of the Mnn− anions (n = 2–16)

Gutsev

Weatherford

Ramachandran

et al. 2015

The Journal of Chemical Physics

View full text Add to dashboard Cite

Photoelectron spectra of the Mnn(-) anion clusters (n = 2-16) are obtained by anion photoelectron spectroscopy. The electronic and geometrical structures of the anions are computed using density functional theory with generalized gradient approximation and a basis set of triple-ζ quality. The electronic and geometrical structures of the neutral Mnn clusters have also been computed to estimate the adiabatic electron affinities. The average absolute difference between the computed and experimental vertical detachment energies of an extra electron is about 0.2 eV. Beginning with n = 6, all lowest total energy states of the Mnn(-) anions are ferrimagnetic with the spin multiplicities which do not exceed 8. The computed ionization energies of the neutral Mnn clusters are in good agreement with previously obtained experimental data. According to the results of our computations, the binding energies of Mn atoms are nearly independent on the cluster charge for n > 6 and possess prominent peaks at Mn13 and Mn13(-) in the neutral and anionic series, respectively. The density of states obtained from the results of our computations for the Mnn(-) anion clusters show the metallic character of the anion electronic structures.

show abstract

Section: Calibration Of Computational Methodsmentioning

confidence: 99%

Photoelectron spectra and structure of the Mnn− anions (n = 2–16)

Gutsev

Weatherford

Ramachandran

et al. 2015

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…One would have to test other functionals to check the validity of this hypothesis, for example, hybrid functionals or the +U formalism. 67 The first solution has been applied to the study of the Mn dimer, 68 and it seems that the addition of a Hartree-Fock part in the exchange term improves the results. However, correlations are known to be weaker in small molecules than in condensed matter.…”

Section: Energy and Stabilitymentioning

confidence: 99%

Phase diagram, structure, and magnetic properties of the Ge-Mn system: A first-principles study

et al. 2011

View full text Add to dashboard Cite

We study the whole Ge-Mn phase diagram with density functional theory (DFT) methods. The 16 known phases are described and trends are analyzed. The compounds are then simulated, allowing a complete evaluation of this method in the projector augmented-wave approach within the collinear spin-polarized framework. Structural parameters, as well as magnetic properties, are compared to experimental values. Stability issues are addressed using a thermodynamic approach based on the grand potential, showing good agreement with experimental data. The impact of semicore electrons and the exchange-correlation functional are also discussed. Finally, it is shown that DFT methods are well suited to study this system, provided that the generalized gradient approximation is used, as opposed to the local density approximation, and correlations between structural errors and Mn concentration are taken into account. In addition, the precision achieved when compared to experiments is 40 meV/atom on energy, ±3% on the lattice parameter, and 0.2μ B /Mn on magnetic moments. Magnetic orders are mostly well reproduced.

show abstract

“…where W D means the weight of doubly excited configuration involved in the diradical pair [81][82][83]. The effective bond order B HOMO after spin projection, normalized information entropy I n and residual information entropy are given, respectively, by…”

Section: Chemical Indices For Labile Mn-o Bondsmentioning

confidence: 99%

Possible mechanisms of water splitting reaction based on proton and electron release pathways revealed for CaMn₄O₅ cluster of PSII refined to 1.9 Å X‐ray resolution

Saitô

Yamanaka

Kanda

et al. 2011

Int J of Quantum Chemistry

View full text Add to dashboard Cite

Recently, Umena et al. have revealed the X-ray diffraction structure of the CaMn 4 O 5 cluster in the oxygen evolving complex (OEC) of photosystem II (PSII) refined to 1.9 Å resolution. Their X-ray structure has first elucidated hydrogen-bonding networks and proton release pathways at OEC of PSII. Here, several working hypotheses Additional Supporting Information may be found in the online version of this article Correspondence to: S. Yamanaka; e-mail: syama@chem.sci.osaka-u.ac.jp Contract grant sponsor: Grants-in-Aid for Scientific Research; Contract grant numbers: 19750046, 19350070, 18350008, 23550016 (heuristic principles) for water splitting reaction are derived from their X-ray structure for theoretical modeling. These hypotheses suggest how water can be oxidized at OEC of PSII: namely possible reaction mechanisms for the reaction. To confirm them, we have also performed broken-symmetry (BS) UB3LYP calculations for active site models based on their XRD structure. The bond lengths of formal Mn(V)AO with labile dp-pp bonds are optimized to clarify possible roles of the species that are often introduced as a key intermediate in the catalytic (Kok) cycle for water splitting reaction at OEC of PSII. Location of the transition structure for the oxygen-oxygen (OAO) bond formation is also performed by the energy optimization technique. The natural orbital (NO) analysis of the UB3LYP solutions has been performed to obtain the natural molecular orbitals and their occupation numbers that have been useful for classification of localized d-electrons, labile chemical bonds and closed-shell (valence) orbitals. The localized d-electrons characterized by the NO analysis are the origins for the magnetism revealed by ENDOR and other magnetic experiments. On the other hand, the nature of labile (soft) dp-pp bonds responsible for the OAO bond formation has been investigated on the basis of chemical indices such as effective bond order (b), diradical character (y), and spin density (Q) indices that are calculated using the orbital overlap between broken-symmetry orbitals. These chemical indices have been calculated for the transition structure of the OAO bond formation at OEC of PSII. Implications of present computational results are discussed in relation to the derived hypotheses and available accumulated experimental results.

show abstract

Density functional study of manganese dimer

Cited by 22 publications

References 81 publications

Photoelectron spectra and structure of the Mnn− anions (n = 2–16)

Photoelectron spectra and structure of the Mnn− anions (n = 2–16)

Phase diagram, structure, and magnetic properties of the Ge-Mn system: A first-principles study

Possible mechanisms of water splitting reaction based on proton and electron release pathways revealed for CaMn₄O₅ cluster of PSII refined to 1.9 Å X‐ray resolution

Contact Info

Product

Resources

About

Density functional study of manganese dimer

Cited by 22 publications

References 81 publications

Photoelectron spectra and structure of the Mnn− anions (n = 2–16)

Photoelectron spectra and structure of the Mnn− anions (n = 2–16)

Phase diagram, structure, and magnetic properties of the Ge-Mn system: A first-principles study

Possible mechanisms of water splitting reaction based on proton and electron release pathways revealed for CaMn4O5 cluster of PSII refined to 1.9 Å X‐ray resolution

Contact Info

Product

Resources

About

Possible mechanisms of water splitting reaction based on proton and electron release pathways revealed for CaMn₄O₅ cluster of PSII refined to 1.9 Å X‐ray resolution