Ab Initio Calculations of the Interaction Potential of the N₂O-N₂O Dimer: Strength of the Intermolecular Interactions and Physical Insights

N₂O, or nitrous oxide, is an important greenhouse gas with a significant impact on global warming and climate change. To accurately model the behavior of N₂O in the atmosphere, precise representations of its intermolecular force fields are required. First principles quantum mechanical calculations followed by appropriate fitting are commonly used to establish such force fields. However, fitting such force fields is challenging due to the complex mathematical functions that describe the molecular interactions of N₂O. As such, ongoing research is focused on improving our understanding of N₂O and developing more accurate models for use in climate modeling and other applications. In this study, we investigated the strength of the intermolecular interactions in the N₂O-N₂O dimer using the coupled-cluster theory with single, double, and perturbative triple excitation [CCSD(T)] method with the def2-QZVPP basis set. Our calculations provided a detailed understanding of the intermolecular forces that govern the stability and structure of the N₂O dimer. We found that the N₂O-N₂O dimer is stabilized by a combination of van der Waals forces and dipole-dipole interactions. The calculated interaction energy between the two N₂O molecules in the dimer was found to be −5.09 kcal/mol, which is in good agreement with previous theoretical and experimental results. Additionally, we analyzed the molecular properties of the N₂O-N₂O dimer, including its geometry and charge distribution. Our calculations provide a comprehensive understanding of the intermolecular interactions in the N₂O-N₂O dimer using the CCSD(T) method with the def2-QZVPP basis set by using the improved Lennard-Jones interaction potential method. These results can be used to improve our understanding of atmospheric chemistry and climate modeling, as well as to aid in the interpretation of experimental data.