Electrides, in which anionic electrons are localized independent of the atoms in the compound, have shown promise especially as catalysts and optoelectronic materials. Here, we present a new computationally designed molecular electride, Li@calix[3]pyrrole (Li@C3P). Electron density and electron localization function analyses unequivocally confirm the existence of localized electride electron density, independent of any specific atoms. Non-covalent interaction plots further validate the character of the isolated localized electron, suggesting that the system can be accurately represented by Li+@calix[3]pyrrole⋅e-, denoting its distinct charge separation. The remarkable non-linear optical properties of Li@C3P, including average polarizability = 412.4 au, first hyperpolarizability = 4.46 × 104 au, and second hyperpolarizability = 18.40 × 106 au, are unparalleled in the previously reported and similar Li@C4P molecular electride. Furthermore, energy decomposition analysis in combination with natural orbital for chemical valence theory sheds light on the mechanism of electron density transfer from Li to the C3P cage, yielding the charge-separated Li@C3P complex. In addition to the electron transfer, a key factor to its electride nature is the electronic structure of the CnP cage, which has its lowest unoccupied molecular orbital located in the void adjacent to the N–H groups at the back of the bowl-shaped CnP cage.

中文翻译：

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新型分子电子化合物的计算机设计和表征：Li@Calix[3]吡咯

电子化合物中阴离子电子的局域化与化合物中的原子无关，特别是作为催化剂和光电材料，已显示出应用前景。在这里，我们提出了一种新的计算设计的分子电子化合物，Li@calix[3]pyrrole (Li@C3P)。电子密度和电子局域函数分析明确证实了局域电子密度的存在，与任何特定原子无关。非共价相互作用图进一步验证了孤立局域电子的特征，表明该系统可以准确地用 Li+@calix[3]pyrrole⋅e- 表示，表示其独特的电荷分离。 Li@C3P显着的非线性光学性质，包括平均极化率= 412.4 au、第一超极化率= 4.46 × 104 au、第二超极化率= 18.40 × 106 au，是之前报道的同类Li@C4P分子电子所无法比拟的。此外，能量分解分析与化学价理论的自然轨道相结合，揭示了电子密度从Li到C3P笼的转移机制，产生电荷分离的Li@C3P复合物。除了电子转移之外，其电子化物性质的一个关键因素是 CnP 笼的电子结构，其最低未占据分子轨道位于碗形 CnP 背面 N-H 基团附近的空隙中笼。