Hi lammps users

I have a question about solving long-range interactions of tip4p/2005 water model. While a tip4p model is proposed in lammps manual to be used for long-range Coulombic solver.

Should we use these parameters instead of what was mentioned in the literature? Or using tip4p/2005 with pppm/disp solver won’t make any mistakes?

Best regards.

All of the params you ask about are inputs to LAMMPS.

I think you are asking if TIP4P params should change

if you use a long-range VDwaals model (dispersion). That’s a Q

for the literature, not really the mail list.

Steve

Thank you Steve,

No, I wonder if I want to use TIP4P/2005 water model with pppm/disp solver, I should change the lammps pppm solver code?

Because, in the following page of the lammps documentation in the TIP4P water models part, different TIP4P water model is proposed for long-range solver. And this question comes to my mind that using different TIP4P model are not supported by longe-range solver. Sorry for my basic question.

**http://lammps.sandia.gov/doc/Section_howto.html#howto-8**

**{"These are the parameters to use for TIP4P with a long-range Coulombic solver (e.g. Ewald or PPPM in LAMMPS):**

**O mass = 15.9994**

**H mass = 1.008**

**. .**

**.**

**"}**

Thank you Steve,

No, I wonder if I want to use TIP4P/2005 water model with pppm/disp

solver, I should change the lammps pppm solver code?

you mean the source code. hell, no!

Because, in the following page of the lammps documentation in the TIP4P

water models part, different TIP4P water model is proposed for long-range

solver. And this question comes to my mind that using different TIP4P

model are not supported by longe-range solver. Sorry for my basic question.

yet, this question is not different from what you asked before and thus

the answer has to be the same. you have to study the literature what are

suitable parameters for what you want to model and what kspace style you

want to use. technically, there is no limitation as to which set of

parameters you use with which coulomb method (cutoff, kspace, msm, dsf,

wolf). LAMMPS will run simulations in either case. whether those are

meaningful and give a good representation is a different question and not a

LAMMPS question, but a question of the science (=> literature).

axel.