Fractional Charge Density Functional Theory and Its Application to the Electro-inductive Effect
Fractional Charge Density Functional Theory and Its Application to the Electro-inductive Effect
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分数电荷密度泛函理论及其在电感应效应中的应用
DOI：
10.1021/acs.jpclett.3c00323
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Baik, Mu-Hyun
中科院分区：
文献类型：
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作者：
Kim, Jun-Hyeong;Kim, Dongju;Yang, Weitao;Baik, Mu-Hyun
我们利用化学势均衡原理证明了分数电子参与了电感应效应和斯塔克振动效应。通过化学势模型，我们能够推断出固定化分子的前沿分子轨道可以为这些效应提供有价值的见解。为了进一步理解和量化这些发现，我们引入了分数电荷密度泛函理论（FC-DFT），这是一种开放系统的正则系综方法。这种方法允许计算电子能量、核梯度和分数电子系统的黑森矩阵。为了纠正小系统近似密度泛函中常见的伪离域误差，我们通过两个相邻整数点的线性插值（LI-FC-DFT）施加了Perdew-Parr-Levy-Balduz （PPLB）条件。虽然这种方法在分子建模方面相对简单，但通过LI-FC-DFT计算得到的结果预测了与实验反应性和固定分子频率变化相同的趋势。
We employed the chemical potential equalization principle to demonstrate that fractional electrons are involved in the electro-inductive effect as well as the vibrational Stark effect. By the chemical potential model, we were able to deduce that the frontier molecular orbitals of immobilized molecules can provide valuable insight into these effects. To further understand and quantify these findings, we introduced fractional charge density functional theory (FC-DFT), a canonical ensemble approach for open systems. This method allows for the calculation of electronic energies, nuclear gradients, and the Hessian matrix of fractional electronic systems. To correct the spurious delocalization error commonly found in approximate density functionals for small systems, we imposed the Perdew–Parr–Levy–Balduz (PPLB) condition through linear interpolation of two adjacent integer points (LI-FC-DFT). Although this approach is relatively simple in terms of molecular modeling, the results obtained through LI-FC-DFT calculations predict the same trend seen in experimental reactivity and the frequency change of immobilized molecules.