Hello Users,
I was unsure where to ask this as this is not directly a LAMMPS question so I apologize. I’m putting together a topography parser that will assign Dreading atom types and then give a LAMMPS data file. I’m a little confused about the use of the C_R (resonance carbon) atom type. I know it would be used for all the atoms in benzene or aromatic rings, but is it also the used for all the carbons in 1,3-butadiene, or would butadiene use the C_2 (SP2 carbon) for all the carbons? I’ve tested both situations and found that bond lengths do not correspond well with several other force fields (UFF, MMFF, MM3) however, I did find by setting carbon 1 and 4 to C_2 and carbon 2 and 3 to C_R that bond lengths and angles better matched actual experimental and force field data.
Thanks for your time and again I apologize for the off topic.