@akohlmey Hi! Can you please suggest the Lammps input script used to replicate the results for dielectric constant that were provided in your slide here (particularly in slide number 21)https://drive.google.com/file/d/1Obfqcl7V0n3B88FDSqh3XKs6Z9LouU4s/view
Also, is there any benchmark script available in LAMMPS to find out dielectric constant of water or a polymer using dipole fluctuation method?
I have tried with this water model provided by Lammps here https://www.lammps.org/bench/inputs/in.spce.txt and compute dipole command with a fix rigid/nvt for 64 molecules, but the results don’t seem to match with your results provided in slide 21.
Please advise.
No. Those simulations where not done with LAMMPS and specifically the analysis was done with a specialized, highly efficient and parallel analysis tool.
This was all done more than 20 years ago and that analysis program has been lost in one of my moves from one job to another. Last time I checked, the Gromacs package had a tool for that, and probably other software packages for MD analysis as well. There is a list of such packages on the LAMMPS homepage.
But all the relevant publications and all the expressions and where I found them are provided in the slides, so it should be possible reproduce the results.
You have to search through the examples folder, but I doubt there is one.
Computing the dielectric constant correctly requires care and attention to detail, especially on the units used. I don’t know you and I don’t know what you have done in your simulation and analysis, so I cannot comment or advise.