Dependence of Properties and Exchange Coupling Constants on the Charge in the Mn2On and Fe2On Series,The Journal of Physical Chemistry A

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Dependence of Properties and Exchange Coupling Constants on the Charge in the Mn2On and Fe2On Series
The Journal of Physical Chemistry A ( IF 2.7 ) Pub Date : 2018-06-05 00:00:00 , DOI: 10.1021/acs.jpca.8b03496
G. L. Gutsev ₁ , K. V. Bozhenko _{2,

3} , L. G. Gutsev ₄ , A. N. Utenyshev ₂ , S. M. Aldoshin ₂

Affiliation

The geometrical structure and properties of the neutral and singly charged Mn₂O_n^q and Fe₂O_n^q clusters (q = 0, ±1) are computed using density functional theory with the generalized gradient approximation in the range 1 ≤ n ≤ 7. The geometrical structures and spin multiplicities of the corresponding species in all six series are similar except for a few exceptions. Antiferromagnetic coupling of total spin magnetic moments of the metal atoms in the lowest total energy states is observed for the majority of species in all six series when n = 1–5; correspondingly, the computed magnetic exchange coupling constants are mostly negative. The states of Mn₂O_n^q and Fe₂O_n^q are nonmagnetic or weakly ferromagnetic when n > 5 except for Mn₂O₇⁺ where the ground state is antiferromagnetic. The computed adiabatic electron affinities and ionization energies of the neutral species in both series are quite close to one another and increase as n increases. However, the binding energies of a single oxygen atom and of an O₂ dimer decrease as n increases and the Mn₂O₇⁺ and Fe₂O₇⁺ cations are barely stable with respect to the O₂ abstraction. The most stable and least stable species at a given n are the anions and the cations, respectively. The electric dipole polarizability per atom decreases sharply when n moves from 1 to 4 and then remains nearly constant for larger n values in the anion series, whereas it is close to the asymptotic value already at n = 2 in the neutral series.

中文翻译：

Mn ₂ O _n和Fe ₂ O _n系列中电荷的性质和交换耦合常数的相关性

几何结构和中性和带单电荷的Mn属性₂ ö _Ñ^q和Fe ₂ ö _Ñ^q群集（q = 0，±1）使用密度泛函理论与范围为1≤广义梯度近似计算Ñ ≤7除了少数例外，所有六个系列中相应物种的几何结构和自旋多重性相似。当n为n时，对于所有六个系列中的大多数物种，在总能量最低的状态下观察到金属原子的总自旋磁矩的反铁磁耦合= 1–5; 相应地，计算出的磁交换耦合常数大多为负。当n > 5时，Mn ₂ O _n^q和Fe ₂ O _n^q的状态为非磁性或弱铁磁性，但Mn ₂ O ₇⁺的基态为反铁磁性。两个系列中的中性物质的绝热电子亲和力和电离能彼此非常接近，并且随着n的增加而增加。但是，随着n的增加和Mn ₂ O的增加，单个氧原子和O ₂二聚体的结合能降低。₇⁺和Fe ₂ O ₇⁺阳离子相对于O ₂抽象而言几乎不稳定。在给定的n下，最稳定和最不稳定的物种分别是阴离子和阳离子。当n从1移至4时，每个原子的电偶极极化率急剧下降，然后在阴离子系列中对于较大的n值几乎保持恒定，而在中性系列中n = 2时已接近渐近值。

更新日期：2018-06-05

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