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 greenhousegaswith a significant impact on global warming and climate change. Toaccurately model the behavior of N2O in the atmosphere,precise representations of its intermolecular force fields are required.First principles quantum mechanical calculations followed by appropriatefitting are commonly used to establish such force fields. However,fitting such force fields is challenging due to the complex mathematicalfunctions that describe the molecular interactions of N2O. As such, ongoing research is focused on improving our understandingof N2O and developing more accurate models for use in climatemodeling and other applications. In this study, we investigated thestrength 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-QZVPPbasis set. Our calculations provided a detailed understanding of theintermolecular forces that govern the stability and structure of theN(2)O dimer. We found that the N2O-N2O dimer is stabilized by a combination of van der Waals forcesand dipole-dipole interactions. The calculated interactionenergy between the two N2O molecules in the dimer was foundto be -5.09 kcal/mol, which is in good agreement with previoustheoretical and experimental results. Additionally, we analyzed themolecular properties of the N2O-N2O dimer,including its geometry and charge distribution. Our calculations providea comprehensive understanding of the intermolecular interactions inthe N2O-N2O dimer using the CCSD(T) methodwith the def2-QZVPP basis set by using the improved Lennard-Jonesinteraction potential method. These results can be used to improveour understanding of atmospheric chemistry and climate modeling, aswell as to aid in the interpretation of experimental data.