Welcome to ARTATOP
Exploring optical properties through atom response theory since 2018!
Nonlinear optical (NLO) materials, which utilize second-harmonic generation (SHG) to achieve laser frequency conversion, are indispensable advanced laser materials. Although extensive exploration has been conducted in this field, the variety and number of available materials remain limited. Moreover, high-performance NLO materials for deep-ultraviolet and mid/far-infrared regions face significant challenges in practical implementation. Therefore, there is an urgent need for high-throughput computational methods to reduce experimental costs, shorten development cycles, and facilitate the efficient development of next-generation NLO materials.
NLO phenomena in crystalline materials originate from photon-electron interactions. Based on translational symmetry and electronic density functional theory, first-principles calculations can now be used to determine the electronic contributions to nonlinear responses. Generally, these results can already be compared with experimental data. However, the information derived from electronic structures is overly complex and lacks sufficient reference value for experimental researchers seeking new materials. Thus, it is necessary to establish general and systematic quantitative structure-property relationships at the atomic scale to explore the essence and manifestation of NLO material genome.
In recent years, we have proposed the concept of a general partial response functional (PRF), which enables the determination of contributions from quantum states at arbitrary energy levels to linear or NLO responses. Based on this, we have developed a NLO atomic response theory (ART). This theory renormalizes first-principles electronic-scale information to the atomic scale within the tight-binding approximation, providing a theoretically rigorous tool for analyzing the origin of NLO effects. It allows for the quantitative determination of contributions from individual atoms and orbitals. This approach has been successfully applied to diverse families of NLO materials—such as borates (KBBF, BBO, LBO, CsB3O5, CsLiB6O10), phosphates (LiCs2PO4, KH2PO4), and chalcopyrites (δ-Ga2Se3, ZnGeP2, CdSnAs2, and related compounds)—revealing how specific atomic species, particularly metal cations, play pivotal roles in enhancing SHG responses. These insights provide a new design perspective beyond traditional empirical approaches.
Building upon these theoretical foundations, we have developed ARTATOP (Atom Response Theory Analysis Toolkits for Optical Properties)—a software package that integrates the ART framework with first-principles crystal calculations. ARTATOP can not only calculate the linear and nonlinear optical properties by employing the “sum over states (SOS)” methods using the results obtained from the VASP or ABINIT optical module, but also provide detailed atomic/orbital-level contributions to these properties based on the ART.
ARTATOP, with its user-friendly operation, multi-functionality, and numerous adjustable parameters, greatly aids researchers in designing and developing NLO materials.
We sincerely hope that ARTATOP will become a powerful tool for researchers in the field of NLO materials, promoting the design and discovery of new NLO materials.