I am looking to perform a simulation with the following constituents:
- TIP4P water droplet in its own vapour
- EAM platinum solid surface
Before getting ahead of myself I’m looking for a good option for the water-Platinum interaction.
In the case of simple LJ-Pt interaction I have in the past used a representative LJ potential with parameters derived for the specific case in question (i.e. Ar-Pt).
However, this simple approach does not seem appropriate to me here, and this is confirmed in the literature where two main options have emerged:
-
Spohr & Heinzinger (S-H): E Spohr, K Heinzinger. A molecular dynamics study on the water/metal interfacial potential. Ber. Bunsenges. Phys. Chem, 1988 (and subsequent publications)
-
Zhu & Philpott (Z-H): ZHU and Philpott. INTERACTION OF WATER WITH METAL-SURFACES. Journal of Chemical Physics (1994) vol. 100 (9) pp. 6961-6968
As noted in Maruyama et al. Molecular scale aspects of liquid contact on a solid surface. Thermal Science & Engineering (2002) vol. 10 (6) pp. 23-29.
Does anyone have experience in using either of these potentials for water-platinum, or an implementation for LAMMPS of the potential functions?
Many thanks!
hi dan,
I am looking to perform a simulation with the following constituents:
- TIP4P water droplet in its own vapour
- EAM platinum solid surface
Before getting ahead of myself I'm looking for a good option for the
water-Platinum interaction.
[...]
However, this simple approach does not seem appropriate to me here, and this
is confirmed in the literature where two main options have emerged:
- Spohr & Heinzinger (S-H): E Spohr, K Heinzinger. A molecular
dynamics study on the water/metal interfacial potential. Ber. Bunsenges.
Phys. Chem, 1988 (and subsequent publications)
Does anyone have experience in using either of these potentials for
water-platinum, or an implementation for LAMMPS of the potential functions?
yup, i have experience with the Spohr/Heinzinger one, since eckhard
spohr was my phd advisor and this kind of stuff was part of his phd work.
if i remember correctly, this is a repulsive morse wall potential with a
corrugation added and then using image charges to model the metal.
i have been thinking for a long time, that it might be a useful thing and
an interesting trip down memory lane to implement image charges
(basically it would need to implement a fix for moving charges without
any other potential attached relative to a mirror plane, so that they
mirror the charge distribution induced in a metal slab), but i have not
yet gotten around to it, mainly because there never was an appealing
enough project that somebody would need it.
if you have explicit platinum atoms, you may want to use explicit (lj or morse)
interactions for the repulsive part and then just use the image charges on top.
cheers,
axel.
Hi Axel
So in Lammps, Is there any potential lammps already have for water/metal interaction?
ziyuan
Hi Axel
So in Lammps, Is there any potential lammps already have for water/metal
interaction?
yes and no. LAMMPS implements a large selection of functional
forms, and for what is not there, you can use tabulated potentials.
whether any of that is a good representation of the behavior of
a metal surface is for you as the user to decide. as was indicated
by dan, there are studies of water films on metals and electrified
surfaces going back more than 20 years in the literature and thus
there is a wealth of experiences to draw from.
the use of image charges is a simple model to represent an ideally
polarizable metal. others include a DFT-like continuum (jellium)
representation that is more material specific and complex pairwise
potentials derived from quantum chemical calculations. i have not
looked into that serious for over 15 years, so i can only provide you
the information that i have not forgotten since.
given the increase in computer power since then, there are also a
large number of studies that use plane wave DFT with pseudopotentials
to avoid parametrization (well, except for the DFT functionals and the
pseudopotentials) entirely or hybrid QM/MM schemes where part
of the system is treated quantum mechanically.
cheers,
axel.
Dear Axel,
Could you please guide me to a reference to learn more about image charges? Are the references provided by Dan few of those? I recently started working on water on metal (aluminum) so it could be useful for me as well.
Best Regards,
Vikas