Dear Justin, Again, thank you very much for your fast reply, which is very clear. However, I'm having difficulties to understand how the tools that I'll use will not depend on the force field parameters.
For example, I'll use gmx_order to compute the order parameter per atom for carbon tails. In order to run this tool, I'll need a tpr file. The tpr file, by definition, will contain the starting structure, the molecular topology and all the simulation parameters: why I have to provide a tpr file to gmx_order, if at the end the parameters that it will contain will not reallly matter? And, If I understood correctly, I can use any force field and its related POPC parameters to generate my tpr file for the analysis that I mentioned above? Many thanks for your help. Zeineb -- Gromacs Users mailing list * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before posting! * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists * For (un)subscribe requests visit https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or send a mail to gmx-users-requ...@gromacs.org.