Finally, for the lowest energy 1:1 complex containing a single Xe atom and a CH3ONO molecule, the binding energy of the complex containing the cis conformer (3A) is -6.11 kJ/mol, while the complex containing the trans conformer (3B) binding energy is -6.13 kJ/mol, see Table . A binding energy difference of +0.03 kJ/mol between the cis and trans complexes with Xe suggests that there is little preference for conformer. When considering all optimized geometries of Xe:CH3ONO, the average binding energy for complexes containing a cis conformer is -4.99 kJ/mol. The average binding energy between Xe and the trans conformer is -4.76 kJ/mol, see Table . For all optimized geometries, the calculations suggest that the cis and trans conformers do not exhibit preferential binding to a particular conformer. These results will be discussed in comparison to the experimental findings in Section 4. The results of the quantum chemistry calculations of the 1:1 van der Waals complexes show that there is preferential binding of the lowest energy rotational isomer-cis-CH3ONO-when deposited with N2, which we extend to provide understanding of the process of diffusion on a surface. Ar and Xe do not exhibit an energetic preference toward the cis or trans conformer, indicating that energetic arguments are not sufficient for rationalizing conformer enhancement upon deposition.