Additionally, the extensive presence of electronegative atoms such as halogens (e.g., in alkyl and vinyl halides, see Figure ) negatively affect the simulations, as halogen bonds typically require atom pairwise corrections . We repeated predictions of the alkyl halides using the GFN2-xTB method that models anisotropic electrostatic interactions and does not employ specific element pair corrections. Though it reportedly improves predictions of molecules containing bonds between molecules with large differences in electronegativity 37 , we did not observe any improvement in spectra quality for our subset . Beyond chemical composition, the related three dimensional molecular structure is the main determinant. While planar geometries are predominantly predicted with high accuracy, central atoms with many rotatable bonds (e.g., P in organic acids, see Figure ) and other stereo centers leads to lower prediction accuracy for the QCxMS method.