Atomate2-ARTATOP: High-Throughput Screening and the Atomic-Level Origin of Second Harmonic Generation in Phosphorus Chalcogenides

Abstract

While phosphorus chalcogenides are promising candidates for infrared nonlinear optical (IR-NLO) applications, a fundamental understanding of the microscopic mechanisms driving their second harmonic generation (SHG) response is still lacking. In this work, we address this gap by developing atomate2-ARTATOP, an open-source high-throughput computational framework that integrates atomic response theory (ART) into atomate2 to enable systematic NLO property screening and analysis. Our large-scale screening of 231 non-centrosymmetric compounds spanning thiophosphates (PS), selenophosphates (PSe), and oxygen-containing phosphorus chalcogenides (PSO) reveals a clear SHG performance trend (PSe > PS > PSO), mapping specific chemical families to targeted infrared and ultraviolet spectral windows. Notably, Hg2P2S7 and InPSe4 exhibit exceptional powder-averaged SHG coefficients of 29.15 (∼2.8 × AGS) and 34.28 pm/V (∼3.2 × AGS), respectively, outperforming the industry standard AgGaS2. Interestingly, unlike conventional thiophosphates, ZnGaPS, a mixed phosphide-sulfide, also exhibits a strong SHG response (21.4 pm/V, ∼2.0 × AGS). Additionally, we identify P2S2O3 as a superior ultraviolet candidate, combining a wide band gap (5.35 eV) with an SHG response ∼7.8 times that of KH2PO4. Through partial response function analysis, we demonstrate that the SHG response is fundamentally governed by nonbonding chalcogen p states, with other elements playing a secondary role on average but contributing considerably in individual compounds. Moreover, the net response in many compounds reflects a competition between positive and negative contributions from different structural units. Finally, by identifying compositional features that induce negative SHG contributions, we offer design insights for enhancing constructive SHG contributions. This work provides a quantitative, orbital-level blueprint for the discovery of next-generation NLO materials.