Data from: Comprehensive first principles study on CO and NO gas adsorption effects on the structural, electronic, and optical properties of ASiSn nanoribbons
Data files
Abstract
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 adsorption, especially in the ultraviolet region. These findings suggest the strong potential of ASiSnNRs for selective and highly sensitive gas sensing applications, particularly for the detection of NO.
DOI: 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, number of atoms, and their positions, either in Direct or Cartesian coordinates. This file defines the geometry of the crystal or molecule before any optimization occurs. Its format is straightforward and crucial for ensuring accurate spatial arrangements of atoms. A small change in POSCAR can significantly affect the physical properties obtained
from the calculation.
KPOINTS: The KPOINTS file defines the grid of k-points used to sample the Brillouin zone in reciprocal space. This grid affects the accuracy of electronic structure and total energy calculations. Typically, a Monkhorst-Pack mesh is used, specified by three integers that determine how finely the zone is divided along each lattice vector. The denser the grid, the more accurate but computationally expensive the calculation becomes. Therefore, KPOINTS helps balance precision and efficiency in VASP simulations.
CONTCAR: The CONTCAR file shares the same format as POSCAR but represents the structure after optimization. It is automatically generated by VASP at the end of a relaxation run. The coordinates in this file show the final atomic positions once the system has reached its minimum energy configuration. Researchers often use CONTCAR as the new POSCAR for subsequent calculations, such as electronic density or band structure analysis. Thus, CONTCAR reflects the equilibrium geometry of the system.
These files can be opened and edited with the Notepad program. In VASP calculations, these input files are required.