Hello

I would like to calculate the average of the radius of gyration of the polymer chains ( contained in the group poly) in my system (which also contains cross-linker molecules).

1). compute 1 poly gyration/molecule

2). compute rgave poly reduce ave c_1

I understand that the first command computes a global vector of the radius of gyration with length of Nmolecules. I am trying to use the compute reduce command to average the values in the vector over all the chains but it gives me the following error:

ERROR: Compute reduce compute calculates global values

I understand that the “compute reduce” documentation specifically requires per atom or local quantities as input in the newer version of LAMMPS. Is there a different way of obtaining averaged values for the radius of gyration vector?

Thank you for your help.

Varun Ullal.