Hi all,

i refereed a paper(J.Phys.Chem.C 2009,113,16906-16914).  in the supporting information they had given total adsorption vs  pressure graph (Figure S9) fron Hydrogen and ZIF-68 as system UFF force  field at 298 K. in the introduction of paper they also mentioned  interaction parameters for C--C sigma 2.8 Angstrom and epsilon 27k, for  H2--H2 sigma 2.960 Angstrom  and epsilon 34.2k ). they obtained result  from Ceirus2 . i tried to reproduce their work( at same no of moves  and cutoff  distance). At 52.3 bar and 298K, i got total adsorption  0.4816%, while data extracting from their graph was 0.35 %. can any one  suggest the source of error and how to insert those interaction parameters for H2 and C---C  in UFF.  because in Material studio only through Drieding force field on can edit  interaction parameters
Thanks
Amar