Dear LAMMPS developers and users,
I am aware of the new “centroid/stress/atom” command as a replacement of “stress/atom” in the cases with “angle, dihedrals and improper contributions”. I am wondering if the command “centroid/stress/atom” works well with Tersoff many-body interactions?
Best wishes,
Yun-Peng Wang
Dear LAMMPS developers and users,
I am aware of the new “centroid/stress/atom” command as a replacement of “stress/atom” in the cases with “angle, dihedrals and improper contributions”. I am wondering if the command “centroid/stress/atom” works well with Tersoff many-body interactions?
have you tried it?
Dear LAMMPS users,
I want to model the system which is included aluminum, nickel and, oxygen. Currently, there are 2 options in terms of force field in LAMMPS which are ReaxFF and COMB. I checked these force fields for pure aluminum and pure nickel but they did not work accurately in terms of predicting the properties that I need to be predicted accurately, then there is no way for me to use ReaxFF or COMB force fields.
There is coul-streitz (ES+) pair style that can be combined with EAM force field and describes all the interactions in aluminum/oxygen system.
ES+ method is able to describe the electrostatic interaction between metals and oxygen, but it has some problems: 1) it is unstable in small distances in terms of charge, 2) It works only for ONE type of metal and oxygen, we cannot add more metal type to the system, because ES+ cannot predict zero charge at the interface of metals.
By all of these problems still I need a force field that is able to describe the interactions between aluminum/nickel/oxygen correctly.
I know there is a new potential called CTIP presented by Zhou. Zhou improved the ES+ method to overcome the shortcoming of ES+. CTIP can be combined with EAM force field and be used for systems included metal (not only one type) and oxygen. CTIP is not implemented in LAMMPS and unfortunately I have no expert to implement this force field in LAMMPS by C++ code.
It is very crucial for me in my PhD project to find a way to model aluminum/nickel/oxygen system in LAMMPS.
If anybody had the same experience or suggestion about it, it would be appreciated. Any solution helps me a lot.
I have to mention I use the lammps27Feb20 version.
Best regards,
Ensieh
How to do realize your PhD is a discussion you need to have with your PhD adviser.
with LAMMPS there is the WYSIWYG principle. what is documented in the manual is available.
LAMMPS does NOT provide potentials outside of what is needed for running the examples.
that is where you need to research from the published literature or look up in the available databases.
if that is insufficient, you need to look for alternatives to classical MD and use semi-empirical or ab initio methods.
if you see a suitable potential, but it is not supported, then you either need to implement it yourself or entice somebody else.
the fact that you need it for your PhD is not a significant motivator for people, though.
so if you really what that model implemented in LAMMPS you have to bite the bullet and obtain the required programming skills.
axel.