and BOSS 38 software packages. However, due to the complex nature of the potential energy surface of the guest molecule, all dihedral scans for PTZ-DBT02 were performed using a new interface with TorsionDrive. In contrast to a regular linear scan, TorsionDrive uses a wave-front propagation method which tends to produce a smoother and more symmetric potential energy surface. This is particularly important for ground state PTZ-DBTO2 because the central nitrogen atom exhibits a change in pyrimidalisation during the scan, which can lead to hysteresis in the torsion scans. Interfaces between TorsionDrive and the Gaussian09 and QUBEKit codes have been developed for this task, and can be accessed on GitHub (). All remaining force field parameters, namely rigid torsion coefficients and those for toluene, were taken from OPLS-AA. No off-centre charges were used in this work.