Nonlinear optical materials have gained immense scientific interest in the recent times owing to their vast applications in various fields. Continuous strides are made to design and synthesize materials with large nonlinear optical response and high thermodynamic stability. In this regard, we present here bi-alkali metal doping on boron phosphide nanocage as a new strategy to design thermodynamically stable materials with large nonlinear optical response. The geometric, thermodynamic, electronic, optical and nonlinear optical properties of complexes are explored through density functional theory (DFT) simulations. The doping of alkali metal atoms introduces excess of electrons in the host (B₁₂P₁₂) nanocage. These electrons contribute towards the formation of new HOMOs, which reduce the HOMO–LUMO gaps of the designed complexes. The HOMO–LUMO gaps of the designed complexes range from 0.63 eV to 3.69 eV. The diffused excess electrons also induce large hyperpolarizability values in the complexes i.e. up to 4.0 × 10⁴au. TD-DFT calculations have been performed for crucial transition states and UV–VIS analysis. Non-covalent interaction (NCI) along with quantum theory of the atoms in molecules (QTAIM) analyses are carried out to understand the bonding interactions between alkali metal atoms and B₁₂P₁₂ nanocage. All the obtained results suggest that bi-alkali metal doped nanocages are exceptionally stable materials with improved NLO response.

近年来，非线性光学材料因其在各个领域的广泛应用而引起了极大的科学兴趣。在设计和合成具有大非线性光学响应和高热力学稳定性的材料方面不断取得进展。在这方面，我们在此介绍了在磷化硼纳米笼上掺杂双碱金属作为设计具有大非线性光学响应的​​热力学稳定材料的新策略。通过密度泛函理论 (DFT) 模拟探索复合物的几何、热力学、电子、光学和非线性光学特性。碱金属原子的掺杂会在主体中引入过量的电子 (B ₁₂ P ₁₂) 纳米笼。这些电子有助于形成新的HOMO，从而减少设计复合物的HOMO-LUMO间隙。设计的复合物的HOMO-LUMO间隙范围从 0.63 eV 到 3.69 eV。扩散的过剩电子还在复合物中引起大的超极化值，即高达 4.0 × 10 ⁴ au。TD-DFT 计算已用于关键过渡态和 UV-VIS 分析。进行非共价相互作用 (NCI) 以及分子中原子的量子理论 (QTAIM) 分析，以了解碱金属原子与 B ₁₂ P ₁₂之间的键合相互作用纳米笼。所有获得的结果表明，双碱金属掺杂的纳米笼是非常稳定的材料，具有改进的 NLO 响应。