I am using the compute dipole to calculate the x,y, and z coordinates of the dipole vector of bulk-water TIP4P. After some tests, I found that the compute dipole does not know anything about the trick that tip4p styles do in LAMMPS. I wonder if someone has thought of a workaround that could take into account the displacement of the massless charge in the dipole computation (or any ad hoc correction) or if implementing a “compute dipole/tip4p” is the only way out. ( I am not considering the implementation of a real four-site model using fix rigid since I am using rerun to extract the dipole vector)

I’d really appreciate any comments or help you can provide.

Paulo Siani, Ph.D.
Università degli Studi di Milano Bicocca
Department of Materials Science

Since TIP4P is a rigid model, the dipole moment is overestimated by a constant factor. Just figure out what that factor is and scale the results and it should be correct.