Hi @abhikeern, No problem. One significant issue that I see is that the kolmogorov/crespi potential seems to be an “Interlayer potential” that requires separate identification of the layers that each atom belongs to in a multi-layer structure (plus the selection of an intralayer potential). This is not a standard approach that is supported by KIM or, as far as I know, GULP.
This potential (ILP) is intended for interlayer interactions between two different layers of graphene. To perform a realistic simulation, this potential must be used in combination with intralayer potential, such as AIREBO or Tersoff potential. To keep the intralayer properties unaffected, the interlayer interaction within the same layers should be avoided. Hence, each atom has to have a layer identifier such that atoms residing on the same layer interact via the appropriate intralayer potential and atoms residing on different layers interact via the ILP. Here, the molecule id is chosen as the layer identifier, thus a data file with the “full” atom style is required to use this potential.
This will make it difficult to create a KIM version of this type of potential. However, we are always interested in working with interested collaborators to make such things available within OpenKIM.