Optical and Miller Model Datasets for 63 NLO Crystals and KCuMoS4

Nonlinear optical (NLO) phenomena play a pivotal role in materials research and technological advancements, particularly for optoelectronic modulation and advanced photonic devices. Accurate evaluation of intrinsic NLO responses is crucial for targeted material discovery and performance optimization. However, conventional NLO coefficients (<i>χ</i>_<em>ijk</em>⁽²⁾) exhibit strong bandgap (<i>E</i>_<em>g</em>) dependence, fundamentally distorting their correlation with actual conversion efficiency (<i>η</i>). This limitation not only impedes fair performance comparisons across materials with different <i>E</i>_<em>g</em> values but also artificially amplifies the NLO capabilities of narrow-<i>E</i>_<em>g</em> systems. To address this critical challenge, we propose an intrinsic NLO metric <i>φ</i>_<em>ijk</em><i>=δ</i>_<em>ijk</em><i>·χ</i>_<em>ii</em>⁽¹⁾, incorporating a static Miller dispersion correction (<i>δ</i>_<em>ijk</em>) that enables cross-<i>E</i>_g evaluations and reveals structural limits of achievable <i>η</i> through fundamental parameter optimization. Our first-principles calculations, performed using our in-house NLOtools, demonstrate the advantage of <i>φ</i>_<em>ijk</em> over <i>χ</i>_<em>ijk</em>⁽²⁾ in decoupling <i>E</i>_<em>g</em> effects while establishing a robust framework for rational design. This framework is demonstrated through the rational design of KCuMoS₄, where targeted skeletal reconstruction and elemental substitution yielded a superior intrinsic NLO potential, confirmed by its concurrently high <i>φ</i>_<em>ijk</em> and normalized <i>Φ</i>_<em>ijk</em> values. The favorable performance of KCuMoS₄ illustrates a route to mitigating the classic trade-off between <i>χ</i>_<em>ijk</em>⁽²⁾ and <i>E</i>_<em>g</em>, providing a practical methodology for the rational design of high-performance NLO materials.

非线性光学（Nonlinear Optical, NLO）现象在材料研究与技术进步中发挥关键作用，尤其适用于光电调制与先进光子器件领域。精准评估本征非线性光学响应，对于定向材料发现与性能优化至关重要。然而，传统非线性光学系数（χ_ijk⁽²⁾）表现出强烈的带隙（E_g）依赖性，从根本上扭曲了其与实际转换效率（η）之间的相关性。这一局限不仅阻碍了不同带隙（E_g）材料间的公平性能对比，还人为夸大了窄带隙体系的非线性光学性能。为解决这一关键挑战，我们提出了本征非线性光学指标φ_ijk=δ_ijk·χ_ii⁽¹⁾，引入了静态米勒色散修正项（δ_ijk），可实现跨带隙（E_g）评估，并通过基础参数优化揭示可实现转换效率（η）的结构极限。我们利用自研NLOtools工具包开展第一性原理计算，结果表明，φ_ijk相较于χ_ijk⁽²⁾在解耦带隙（E_g）影响方面更具优势，同时为合理材料设计构建了一套稳健的框架。我们通过KCuMoS₄的合理设计验证了该框架：通过定向骨架重构与元素取代，获得了优异的本征非线性光学潜力，其同时具备高φ_ijk与归一化Φ_ijk值，证实了该设计的有效性。KCuMoS₄的优异性能表明，该方案可缓解χ_ijk⁽²⁾与带隙（E_g）之间经典的权衡矛盾，为高性能非线性光学材料的合理设计提供了实用方法。