First-Principles Calculation of the Three-Dimensional Potential Energy Surface of Li₂O for Nanoelectronic and Optoelectronic Applications

Lithium oxide (Li 2 O) plays a critical role in lithium-ion batteries and emerging optoelectronic materials, where its structural stability and electronic interactions determine performance. Despite its significance, a comprehensive three-dimensional potential energy surface (PES) for Li 2 O remains unexplored, limiting predictive models for nanoscale applications. In this study, we present the first high-precision ab initio calculation of the ground-state PES of Li 2 O using coupled-cluster theory with single, double, and perturbative triple excitations (CCSD(T)). A total of 1140 energy points were computed using a mixed basis set (aug-cc-pCVTZ) with bond functions, ensuring accuracy near equilibrium. The fitted analytical PES exhibits minimal deviation (0.0732% max error) and reveals two distinct potential wells at 0° (linear Li–O–Li, depth: −9.8753 eV) and 90°(T-shaped, depth: −0.1374 eV), aligning with experimental data. These findings provide critical insights into Li 2 O’s stability, reaction pathways, and vibrational modes, which are essential for optimizing its role in solidstate electrolytes and interfacial layers in batteries. Furthermore, the anisotropic PES suggests implications for charge transport and excitonic behavior in optoelectronic devices. This work establishes a foundational framework for simulating Li 2 O’s dynamic behavior in nanostructured environments, enabling future studies on collision-induced absorption, ion transport, and defect engineering in nanoelectronics. The results bridge theoretical chemistry with applied materials science, offering predictive tools for designing Li 2 O-based nano-materials with enhanced efficiency in energy storage and optoelectronic systems.