; In this topology include file, you will find position restraint ; entries for all the heavy atoms in your original pdb file. ; This means that all the protons which were added by pdb2gmx are ; not restrained. [ position_restraints ] ; atom type fx fy fz 1119 1 1000 1000 1000 1121 1 1000 1000 1000 1123 1 1000 1000 1000 1125 1 1000 1000 1000 1126 1 1000 1000 1000 1127 1 1000 1000 1000 1129 1 1000 1000 1000 1130 1 1000 1000 1000 1131 1 1000 1000 1000