As with most properties derived from molecular structure, topological symmetry has a non-negligible influence on TABS and nTABS. In this context, symmetry contributes both at the global (full molecule) and local (bond environment) levels. Local symmetry, where at least one of the two atoms constituting a bond is connected to multiple symmetry-equivalent atoms, intuitively should result in a reduction in the number of distinguishable torsion states. In simple cases, where the local symmetry is isolated and no other global symmetries exist, this results in different bins of the torsion profile being equivalent. However, the integration of local symmetry in the algorithms for TABS and nTABS is problematic. Taking 1,3,5-triethylbenzene as an example, there are three torsions identified, marked in blue in Figure , each of which has a multiplicity of two. Each of the three torsions of this molecule includes a topological symmetry group with the atoms in the phenyl ring neighbouring the atom that connects the ring to the substituents. This implies a mirror plane, which reduces the torsional space of each bond by a factor of two. Naively taking two bins to be the same for torsions with a multiplicity of two would result in the bins being merged, yielding in a nTABS of 1. This is clearly not the case, as can be seen from the two different conformers depicted in Figure . This simple example shows that the decision on whether a local topological symmetry results in a reduction in the number of bins in a torsion profile cannot be made without considering the overall molecular symmetry. The two overall configurations in Figure can be labeled as [above, above, below] and [above, above, above].