Dimensional classification and shape reliability in In_xSe_y clusters and 2D materials: a quasi-molecule perspective...

Area of Science:

• Computational chemistry
• Materials science
• Electronic-structure theory

Background:

• Predicting molecular and material shapes from compact basis sets is a significant challenge in electronic-structure theory.
• Understanding the dimensional classification (linear, planar, etc.) of 2D Indium-Selenium (In_xSe_y) clusters and materials is essential for materials design.

Purpose of the Study:

• To investigate the dimensional classification of 2D In_xSe_y clusters and materials using density-functional theory (DFT) with subminimal basis sets.
• To assess the reliability of the compact STO-3G basis set in preserving the dimensional character of chemical-bound systems.

Main Methods:

• Utilized density-functional theory (DFT) within the quasi-molecule framework.
• Employed the compact STO-3G basis set for dimensional classification of 2D In_xSe_y systems.
• Performed optimizations with split-valence and polarized basis sets to confirm robustness.

Main Results:

• The STO-3G basis set accurately preserves the dimensional character (linear, planar, etc.) of 2D In_xSe_y systems.
• Structural topology is robust to basis-set truncation, confirmed by optimizations with larger basis sets.
• Essential bonding and geometry features are encoded in the valence-orbital symmetry of quasi-molecular systems.

Conclusions:

• Subminimal basis sets, like STO-3G, are suitable for exploring cluster properties and predicting dimensional character.
• The study clarifies the limits of geometry as an emergent property of the Born-Oppenheimer surface.
• Findings support the rational use of compact basis sets for computational materials science and provide insights into crystalline lattices.