I am trying to calculate the dielectric constant of bulk water. According to this post replied by you as well
https://matsci.org/t/can-anyone-help-me-understand-why-my-dielectric-constant-calculation-is-not-leading-to-the-correct-result/33032
I am testing the results of computing the total dipole moment by summing over the dipole moments of the individual water molecules and over individual charges. For the latter, I have to use each atom as a chunk and calculate the dipole moment for each chunk, followed by sum them up. This is why need to teat per atom as a chunk.