Abstract

The structural parameters of Eu@C₆₀ isomers and the squared electron spin <Ŝ²> have been calculated using the quantum-chemical DFT (U)PBE0 method with variable quantum numbers M_S. The (C_2v) isomer (M_S = 7/2, <Ŝ²> = 15.76 a. u.) includes a triatomic EuC₂ fragment with a degraded C=C bond (2.565 Å), common for two 6-atom cycles. Two (C_3v) isomers (M_S = 7/2±1, <Ŝ²> = 17.76±7.01 a. u.) include the hexagonal pyramid EuC₆. The energies of the isomers differ by no more than 0.046 eV. The energy barriers allow pseudo-rotation of the molecule. The Eu endo atom increases the reactivity of the carbon shell of C₆₀ and stabilizes the (Eu@C₆₀)₂ nano-dumbbell. The <Ŝ²> values are 56 and 90 a. u. for the structures of similar energy, (C_i)-(Eu@η²-C₆₀)₂ and (C_i)-(Eu@η⁶-C₆₀)₂, with Eu∙∙∙Eu distances of 10.35 and 10.08 Å, respectively.

中文翻译：

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内六面体Eu @ C 60和（Eu @ C 60）2金属富勒烯的结构建模

摘要

铕@ C的结构参数_60分异构体和平方电子自旋<S ² >在使用量子化学DFT（U）PBE0方法具有可变量子数M被计算_小号。（C _{2 v}）异构体（M _S＝ 7/2，＜² > ＝ 15.76au）包括具有降解的C ＝ C键（2.565）的三原子EuC ₂片段，在两个6原子循环中是共同的。两个（Ç _{3 v}）异构体（M_小号= 7/2±1，<S ² > = 17.76±7.01 AU）包括六角锥EUC ₆。异构体的能量相差不超过0.046 eV。能量屏障允许分子假旋转。Eu内原子增加C ₆₀碳壳的反应性，并稳定（Eu @ C ₆₀）₂纳米哑铃。所述<S ² >的值是56和90 AU为相似的能量的结构，（Ç_我） - （铕@η ² -C ₆₀）₂ 和（ç_我） - （铕@η ⁶ -C ₆₀）₂， Eu∙∙∙Eu距离分别为10.35和10.08Å。