Comprehensive first principles study on CO and NO gas adsorption effects on the structural, electronic, and optical properties of ASiSn nanoribbons

This paper presents a detailed first-principles investigation of the effects of CO and NO gas molecule adsorption on the structural, electronic, and optical properties of armchair SiSn nanoribbons (ASiSnNRs). Cohesive and adsorption energy calculations indicate that the ASiSnNR structure is thermodynamically stable, with physisorption for CO (−0.01 eV) and chemisorption for NO (−0.68 eV). Electronic band structure analysis reveals that pristine ASiSnNR exhibits semiconducting behavior with a narrow band gap (~0.43 eV), which slightly widens upon CO adsorption and transitions to a metallic state upon NO adsorption, due to strong orbital hybridization and charge transfer effects. Charge density and wave function analyses confirm this mechanism, with particular emphasis on the role of the π* orbital of the CO molecule. The dielectric function, optical absorption, reflection spectra, and joint density of states (JDOS) show significant enhancements in anisotropic optical properties after CO ..., , # Comprehensive first principles study on CO and NO gas adsorption effects on the structural, electronic, and optical properties of ASiSn nanoribbons

DOI: [https://doi.org/10.5061/dryad.2jm63xt1s](https://doi.org/10.5061/dryad.2jm63xt1s)

## Description of the data

**INCAR**: The INCAR file is the main control file in VASP that defines how the calculation is performed. It contains parameters such as the energy cutoff (ENCUT), convergence accuracy (EDIFF), ionic relaxation settings (IBRION, ISIF, NSW), and spin treatment (ISPIN, MAGMOM). Each tag specifies how VASP should handle electronic iterations, geometry optimization, and output files. By adjusting these tags, users can switch between relaxation, static, or molecular dynamics calculations. Essentially, INCAR determines the precision and type of simulation.

**POSCAR**: The POSCAR file provides the initial atomic structure and lattice information for the simulation. It includes the scaling factor, lattice vectors, element names, n...,