To compare this new approach with the ex-isting cartesian-based initial guesses, NEB calculations were performed on several chemical reactions, each one starting with an IC interpolation, a simple cartesian interpolation, and an IDPP-preoptimized cartesian interpolation, as described in the paper of Smidstrup et al. The reactions are shown in Figure . Reactions R1-R3 provide classical examples of organic chemistry reactivity, with the dimerization of cyclopentadiene (R1), the Alder-ene reaction between ethene and propene (R2) and the cleavage of sulfolene (R3). Reactions R4-R5 are two selected nucleophilic reactions of carbocations. The last three reactions R6-R8 are rearrangement reactions in molecular dimers without bond breaking/formation events. One should note that R6 corresponds to a conversion from an O-bonding to a π-bonding dimer of furan and methanol, while R7 should describe the translation of methanol from one side of the furan molecule to the other. Albeit not a thorough benchmark set, it does provide some common tasks one faces in reaction path optimisations. The theory level used for the calculation of the R7 reaction (see Figure ) was PBEh-3c, and for all other calculations, it was HF-3c. Climbing Image 42 was used in conjunction with variable spring constants, as described by Henkelman and Jónsson. In all cases we made use of eleven intermediate points (or "images"). The optimization algorithm used was a modified version of Momentum Gradient Descent. The related equations, as well as the definitions of its parameters can be found in appendix C. The parameterisation used in this work is provided in the Supporting Information. Our NEB implementation was interfaced to Orca, with the minima also provided by the software package. Further computational details are provided in the Supporting Information.