Mineral‐Inspired and Computation‐Assisted Rational Design of Polar Gittinsite‐Type Thiophosphates With Exceptional Nonlinear Optical Performance

ABSTRACT

Polar chalcogenides have emerged as a vibrant class of candidates for infrared nonlinear optical (NLO) applications. However, achieving a balance between large NLO response and wide bandgap within a polar structure remains a crucial challenge. Here, we present a mineral‐inspired and computation‐assisted creation strategy that integrates crystallographic intuition from natural prototypes with first‐principles screening of functional [P _x S _y ] motifs. Guided by this approach, 13 thiophosphates were successfully identified and synthesized, including 8 polar gittinsite‐type ones, AM ^III P ₂ S ₇ (A = K, Rb, Cs; M ^III = V, Cr, In, La, Bi). As a representative, the structure of RbInP ₂ S ₇ features [InP ₂ S ₁₁ ] six‐membered rings built by the asymmetric integration of [InS ₆ ] octahedra and [P ₂ S ₇ ] dimers, resulting in strong local polarity and robust covalent In–P–S linkages. RbInP ₂ S ₇ exhibits a large NLO response (2.3 × AgGaS ₂ ), wide optical bandgap (3.08 eV), and high laser‐induced damage threshold (13.9 × AgGaS ₂ ), surpassing most reported NLO chalcogenides. This study not only uncovers a high‐performance NLO crystal but also establishes a generalizable design paradigm that integrates mineral‐inspired chemistry with theoretical screening—offering valuable guidance for the rational discovery of future functional chalcogenides.