我们能在多大程度上准确描述自旋交叉？
How Accurately Can We Describe Spin Crossover?
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中文总结 AI 辅助
本研究通过逆向工程实验转变温度，拟合LC-$\omega$PBE泛函的范围分离参数，系统获取自旋交叉能量，并评估了泛函差异、参数敏感性和耦合簇方法的影响。
中文摘要 AI 辅助
具有热自旋交叉的金属配合物复杂的物理化学性质使得常规电子结构计算难以准确预测转变温度 $T_{1/2}$。困难在于自旋交叉能量（一种分子光谱性质）与 $T_{1/2}$（一种凝聚相性质）之间的复杂联系。在此，我们展示了如何通过对实验 $T_{1/2}$ 数据进行逆向工程来系统地获得自旋交叉能量。该协议基于拟合混合 LC-$\omega$PBE 密度泛函中的范围分离参数 $\omega$，以重现一系列金属配合物的实验 $T_{1/2}$ 值。我们通过将常见交换和相关泛函的性能与我们的参考数据进行比较，深入分析了至少 $\pm 15$ kJ mol$^{-1}$ 差异的来源。通过分析转变温度对范围分离参数 $\pm 1$\\% 变化的敏感性，我们确定了它们典型的 $\pm 50$ K 不确定性，以及由于 $T_{1/2}$ 的 $\pm 1$\\% 变化导致提取的自旋交叉能量的 $\pm 2$ kJ mol$^{-1}$ 不确定性。最后，我们展示了参考数据集中八个较小分子的高水平全电子耦合簇方法的结果，并讨论了激发序列截断对自旋态能量的影响。
英文摘要
The complicated physicochemical properties of metal complexes that exhibit thermal spin crossover make it difficult for routine electronic structure calculations to yield an accurate transition temperature prediction, $T_{1/2}$. The difficulty lies in the intricate connection between the spin-crossover energy, which is a molecular spectroscopic property, and $T_{1/2}$, a condensed phase property. Here we show how to obtain spin-crossover energies systematically by reverse engineering of experimental $T_{1/2}$ data. The protocol is based upon fitting the range separation parameter, $ω$, in the hybrid LC-$ω$PBE density functional to reproduce the experimental $T_{1/2}$ values for a series of metal complexes. We provide insights into the sources of variations of at least $\pm 15$ kJ mol$^{-1}$ found from common exchange and correlation functionals by comparing their performance against our reference data. By analysis of the sensitivity of transition temperatures to $\pm 1$ \% shifts in the range separation parameter, we determined a typical uncertainty of $\pm 50$ K for them, and a $\pm 2$ kJ mol$^{-1}$ uncertainty in the extracted spin-crossover energies due to $\pm 1$ \% variations of $T_{1/2}$. Lastly, we present results from the high-level, all-electron coupled cluster method for eight of the smaller molecules in the reference data set, and discuss the influence of the truncation of the excitation series upon the spin state energies.
