Coulombic cutoff of TIP4P/ICE model

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1

Hi lammps users,
Now, I am performing simulations of ICE melting with TIP4P/ICE model.
I am doubt about the parameter setting of Coulombic cutoff of this model.
In the LAMMPS manual (http://lammps.sandia.gov/doc/Section_howto.html#howto_8), a cutoff of Coulomb is
used, which suggests a cutoff model, such as pair_style lj/cut/tip4p/cut.
However, in the original work of TIP4P/ICE ((J Chem Phys, 122, 234511 (2005); http://dx.doi.org/10.1063/1.1931662)),
the long range Coulombic interaction was considered using Ewald summation technique (EST).
So, my question is should I consider the long-range electrostatic force (with PPPM) or without consideration for TIP4P/ICE
model in LAMMPS.

2

Hi lammps users,
Now, I am performing simulations of ICE melting with TIP4P/ICE model.
I am doubt about the parameter setting of Coulombic cutoff of this model.
In the LAMMPS manual (http://lammps.sandia.gov/doc/Section_howto.html#howto_8), a cutoff of Coulomb is
used, which suggests a cutoff model, such as pair_style lj/cut/tip4p/cut.

Please read the text more carefully. It says that you can use either. The original tip4p was, of course, parameterized for cutoff, but that is not the model you want.

3

Thanks for you reply.

The original tip4p/ic was not setting cutoff for electrostatic force((J Chem Phys, 122, 234511 (2005); http://dx.doi.org/10.1063/1.1931662)),

But in lammps manual, there is a cutoff of Coulomb with a ciatation of this orignal paper (as shown above). The parameters setting are different with its citation, that is what I am puzzling.

Bests,

NIngwei

4

Thanks for you reply.

The original tip4p/ic was not setting cutoff for electrostatic force((J Chem
Phys, 122, 234511 (2005); http://dx.doi.org/10.1063/1.1931662),

i didn't say that. i referred to the original TIP4P paper to which
model you were pointing with the URL to the LAMMPS manual. that
segment clearly says first: you can use either lj/cut/tip4p/cut for a
cutoff model or lj/cut/tip4p/long and pppm/tip4p for a long-range
electrostatics based model. *then* it lists the parameters for the
original tip4p model (with reference to the jorgensen paper), which
*is* a cutoff model, then tip4p/ice, then tip4p/2005 and tip4p/ew,
i.e. the version of the original tip4p reparameterized for long-range
electrostatic. all logical, systematic, and not confusing (to me) at
all.

But in lammps manual, there is a cutoff of Coulomb with a ciatation of this
orignal paper (as shown above). The parameters setting are different with
its citation, that is what I am puzzling.

where exactly are they different?

what i find more puzzling is your ability to misread documentation
(and e-mails). could it be that your screen is dirty and needs to be
cleaned?

axel.