First-Principles Insights into Superalkalis/Superhalogens-Doped Be₁₀O₁₀ Nanoring for Enhanced Harmonic Generation and Nonlinear Optical Response

Abstract

By using the ωb97xd/6–31G(d,p) DFT approach, the enhanced structural, electrical, and optical properties of the Be₁₀O₁₀ doped with superalkali and superhalogens were investigated. The adsorption energies of the dopant molecules on Be₁₀O₁₀ indicate that their complexation is feasible. According to the DOS analysis, a new molecular orbital with the greatest energy has formed in the combined structure of the dopants and nanoring. As a consequence, the energy gap of the complex structures Li₄O-Be₁₀O₁₀-II (4.181 eV) and AlF₄-Be₁₀O₁₀-I (5.361 eV) seems to be significantly reduced. By using EDDM techniques, the NLO properties of the investigated complexes were evaluated. According to the EDDM findings, hyperpolarizability is enhanced by a donor-acceptor process that occurs when electrons are transferred from the Be₁₀O₁₀ to the dopants. The complexes exhibit isotropic NLO behavior with complex Li₄N-Be₁₀O₁₀-II showing high α_aniso (1.21 × 10² a.u.) value. Doped isomers achieve high hyperpolarizability values of β = 9.91 × 10³–2.05 × 10⁴ a.u with enhanced noncovalent interactions. Additionally, the computed second harmonic generation (SHG) β (−2ω, ω, ω) and the electro-optical Pockels effect (EOPE) β (−ω, ω, 0) at the frequencies of ω = 1064 nm (0.0428 au) and ω = 532 nm (0.0856 au) validate that all Be₁₀O₁₀ based isomers are potentially effective for high-performance nonlinear optical devices.