Dear Axel
Thanks for your prompt response.
Through my question sounds physically, it concerns the malfunction of the LAMMPS.
as i said before, there are many possible reasons for things not working as expected. claiming there is a malfunction in LAMMPS is making a strong statement and conflicting with many other calculations that work as expected. if you are convinced that LAMMPS is at fault, you need to provide much more convincing evidence than the simulation not behaving as you expect. like real numerical differences.
Before proceeding to simulation, I thoroughly skimmed over papers, All of them notified a smooth meniscus front for the flow of water in mineral channels like below.
what i see here is water creeping up the walls just in your system. however, there seems to be a much larger reservoir than in your, a vacuum region in z-direction, and non periodicity in x. at least that is what the pictures you show here suggests. the fact that the water does not follow could be attributed to the too small water reservoir. water has to come from somewhere to fill the slit.
Kspace is necessary for realistic simulation but it’s not working at all for my case!
As notified before, my system nicely reproduces the expected flow front by ignoring long-range forces, however, it’s progress rate does not comply with what reported in the literature.
I think something is wrong with the settings of the kspace but I don’t know how to deal with.
It may be a bug or numerical issue with the current stable release of LAMMPS.
i strongly disagree. there is no evidence here confirming this. your setup does not look identical to the images you quote.
The GPU package complied with last released CUDA under instruction in the manual.
that doesn’t tell me the settings you choose to compile and since “last stable” and “last released” version is a term depending on the date when somebody looked it up, it is more scientific and accurate to state the exact version information. and while you are at it, also provide information on the platform you are running on.
looking back at the history of people claiming that LAMMPS has a bug because simulations don’t behave as expected, your probability of being correct is extremely low. almost all of the cases where people had similar claims that yours could be traced back to bad input parameters or bad construction of the simulation setup. so i caution you to not make any claims that cannot be sustained. the scientific approach is to carefully investigate the situation and provide convincing evidence, that numbers produced by LAMMPS are off. e.g. forces for non-kspace and kspace coulomb interactions have to converge to the same values for growing cutoffs of the non-kspace coulomb compared to kspace with sufficiently well converged settings. also, you have to check that GPU and CPU are producing converging results when compiling with since, mixed and then double precision.
axel.