Density functional study of FeO2, FeO, and FeO
Density functional study of FeO2, FeO, and FeO
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FeO2、FeO 和 FeO 的密度泛函研究
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发表时间：
2000
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影响因子：
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通讯作者：
M. Castro
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作者：
Alfonso T. Garca;M. Castro
最低能量结构的FeO 2的确定通过密度泛函理论技术，在程序DGauss 3.0.1中实现。所进行的计算是使用两个理论水平的全电子类型，即使用Vosko-Wilk-Nusair（VWN）泛函的局域自旋密度近似和Becke（1988）交换和Perdew（1986）相关泛函形式的广义梯度近似（GGA）。结果通过程序UniChem可视化。计算了Fe（O）2，C2 v; Fe（O）2，D∞h; Fe（η2-O2），C2 v; Fe（η1-O2），Cs;和Fe（η 1-O2），C∞v的键长和键角以及总能量。分子轨道和谐波振动分析进行了这些物种，除了Mulliken人口分析。单正，负电荷的物种也被认为是充分的几何优化的自洽场（SCF）梯度方法。精确的电离势和电子亲合势（垂直，v，和绝热，a，测定），从而能够计算。结果表明，对于基态（GS）Fe（O）2，C2 v，M=3：δ OFeO=138.1°（133.6°）[括号中的值为局域自旋密度近似（LSDA）-VWN，而其他值为GGA-B88/P86水平]。在此，Re Fe-O=1.60 A（1.57 A），ET=−1414.2064 Au（− 1，410.5047 Au），EAa=2.47（2.60）eV，IPa=10.6（10.5）eV，EAv=2.41（2.20）eV，IPv=10.67（10.63）eV，EAexp=2.349 eV（与相关研究一致）。在GS中的分子氧分子被发现是解离的，相比那些具有协调模式的O2分子形式上持续存在的状态。铁原子的3d 4sp配置被发现是特别相关的Fe-O键的形成。所涉及的铁-氧和氧-氧键的特征。观察到这些电子和结构性质之间的直接关系，也影响给定分子的总能量。© 2000 John Wiley & Sons，Inc. Int J Quant Chem 80：307-319，2000
The lowest energy structures of FeO2 were determined by means of density functional theory techniques as implemented in the program DGauss 3.0.1. The calculations performed were of the all-electron type using two levels of theory, namely the local spin density approximation with the use of the Vosko–Wilk–Nusair (VWN) functional and the generalized gradient approximation (GGA) in the form of the Becke (1988) exchange and Perdew (1986) correlation functionals. Results were visualized by means of the program UniChem. Bond distances and angles as well as total energies were calculated for several states of the moieties: Fe(O)2, C2v; Fe(O)2, D∞h; Fe(η2-O2), C2v; Fe(η1-O2), Cs; and Fe(η1-O2), C∞v. Molecular orbital and harmonic vibrational analyses were carried out for these species, in addition to Mulliken population analyses. Singly positive and negative charged species were also considered and fully geometry optimized in a self-consistent field (SCF) gradient method. Accurate ionization potentials and electron affinities (both vertical, v, and adiabatic, a, determinations) were thus able to be computed. The results show the following for the ground state (GS) Fe(O)2, C2v, M=3: ∠OFeO=138.1° (133.6°) [values in parentheses are for local spin density approximation (LSDA)–VWN, while the others are at the GGA-B88/P86 level]. Here, Re Fe–O=1.60 A (1.57 A), ET=−1414.2064 au (−1,410.5047 au), EAa=2.47 (2.60) eV, IPa=10.6 (10.5) eV, EAv=2.41 (2.20) eV, IPv=10.67 (10.63) eV, and EAexp=2.349 eV (in agreement with related studies). In the GS the dioxygen molecule is found to be dissociated, compared to those states which have coordination modes where the O2 molecule formally persists. A 3d4sp configuration for the iron atom is found to be especially relevant in Fe–O bond formation. The iron–oxygen and oxygen–oxygen bonds involved are characterized. A direct relationship is observed between these electronic and structural properties, influencing also the total energy for a given molecule. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 80: 307–319, 2000