Flexible SPC water

Please post to the list, not to me.

The msi2lmp tool does not know anything about coeffs. It just

uses what ever force field file you give it. I have no idea if

the CVFF file(s) packaged with the tools are current, or one

of many choices. It’s really up to you to provide the files

you want to use that are parameterized for what you want

to simulate. You have Materials Studio, so you can use

whatever files it provides as input to msi2lmp.


a few additional comments:

there are many, many publications of variants of well known water potentials and also, many times water potentials are adjusted when used for a particular force field. the classic example is TIP3P in CHARMM, which is different from the origin TIP3P potential (it actually matches a potential published as TIPS2 which is a variant of TIP3P, if i remember correctly).
as for which variant to choose, the general consensus is to use the potential parameters that are bundled with the force field and thus consistent with the parameters of the remaining atom types. particularly changing the water potential parameters can cause lots of problems, since most parameters are specifically tuned for that water model. this is why people still use “old” water potentials, even though there are “better” variants available, since the switch of the water potential would require to reparameterize everything else as well, which is almost always not a viable solution.

as for msi2lmp. the bundled parameter files have to be freely redistributable. the force field files in bundled with MS contain licensed proprietary information and thus they cannot be bundled with msi2lmp.