There are many methods and software for simulating materials in practice today, each software or computational method has its own advantages and disadvantages. In the process of studying and researching material simulation, we found that the VASP software combined with the Density Functional Theory (DFT) method is perfect up to this point. Reliability, accuracy, and low resource and time consumption during the calculation process are the standout advantages of this combination. DFT calculations on VASP require the precise construction of input data, including the input files, and it is not necessary to write code to process the output data, which is a significant advantage compared to other methods. Output data is processed through commonly used support software such as Origin and VESTA, which is an advantage of this simulation calculation method.

The paper presents the results of a study on the essential physical properties of armchair SiSn nanoribbon (SiSnNR) material, based on density functional theory (DFT) using the quantum simulation program VASP. Structural parameters are highlighted along with electronic and optical properties. The findings reveal that SiSnNR exhibits significant differences in bond lengths, bond angles, and buckling compared to SiNR and SnNR. SiSnNR demonstrates semiconducting properties, with a direct band gap width of approximately 0.3123Å calculated using GGA-PBE, increasing to 0.5892Å when using the hybrid HSE06 functional. The results indicate that Sn atoms primarily contribute to energy bands below the Fermi level, while Si atoms contribute more to higher energy levels. The study also highlights the overlap of py and pz orbitals, leading to sp2 and sp3 hybridization. In terms of optical properties, the energy range from 3 to 5eV is where SiSnNR exhibits the strongest light absorption. The largest number of electron-hole pairs is generated within the energy range of 8-10eV, resulting in intense optical absorption and transitions in this region.