Questions tagged [interatomic-potentials]

Questions related to the various types of interatomic potentials that are used in materials modeling.

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8
votes
1answer
123 views

Considerations when developing ab initio based interatomic potentials for classical molecular dynamics

I know that there are published interatomic potentials provided for most elements when using classical molecular dynamics tools such as LAMMPS. However, if someone were to use their own DFT ...
10
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2answers
174 views

Qualitatively, How do MEAM Potentials Work?

I have frequently come across MEAM potentials in my work, but I lack an intuitive understanding of what they do. What's a good qualitative description of a MEAM potential function?
6
votes
1answer
44 views

What is the meaning of Coulomb Subtraction?

Specifically, in the General Utility Lattice Program (GULP) 2003 paper, in the methods section on Two-body Short-range Interactions we have the following: For covalently bonded atoms, it is often ...
7
votes
1answer
59 views

How Do you Produce your own MEAM Potentials?

I have come across the MEAM Parameter Calibration toolkit (link leads to Wiki, video tutorials, and download link for the package) for fitting your own MEAM potentials [1]. Is this the best software ...
6
votes
0answers
76 views

How do you Select a Time Step for Molecular Dynamics Simulations?

It seems there is a general agreement among the practitioners of Molecular Dynamics that 1fs is a fairly reasonable time step, with shorter time steps being required for materials with higher ...
3
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0answers
45 views

Problems with Lennard Jones potential parameters reading [closed]

So I was given this link, and was happy that I have now the epsilons and sigmas that I can use in Lennard-Jones potential calculations, but found out that the information in other sources is very ...
5
votes
1answer
126 views

What is the equilibrium bond length for a Lennard-Jones potential?

If I have $\epsilon$ and $\sigma$ can I calculate equilibrium distance $r_e$ in one run? What I have tried is to put $V = \epsilon$ and bring out the $r$ from the formula, but it seems not solvable. ...
8
votes
1answer
120 views

Where to get Tersoff and SW potentials for LAMMPS

I want to do some molecular dynamics simulations for silicene with hydrogen and halogen atoms deposited at the surface. Where can I find Stillinger-Weber potentials to use for this? There doesn't seem ...
14
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1answer
230 views

Creating Interatomic Potential for Lammps using DFT

What are the basic steps and methodologies used in creating inter-atomic potential (specially EAM, MEAM potentials) for metals ...
7
votes
4answers
851 views

How to create a lookup table of ϵ and σ values for Lennard-Jones Potentials?

So in my last question How may I calculate the bond length between two atoms? I mentioned that I want to use Lennard-Jones Potential to simulate atom/molecule interaction for my sandbox-game-like ...
12
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6answers
1k views

How may I calculate the bond length between two atoms?

I have been looking into Lennard-Jones Potential and Morse potential. And what the formulas do is to calculate a potential and the 'well depth' and 'distance at which the intermolecular potential ...
16
votes
6answers
2k views

How do I simulate the interaction between two atoms?

I want to build a rough atom interaction simulator, where pushes two (or more) atoms toward each other and they should behave physically correctly: attract, bond or repel with some force. So that is ...
10
votes
1answer
59 views

Reading complex potential into CP2K

Is it possible to read a complex potential into CP2K? I have generated a potential using FDTD at a given frequency, which results in a complex result. The potential is to be read in to a real time ...
17
votes
2answers
2k views

What is the cutting edge for open-source Force-Field generation?

The adoption of atom-typing allowed for the creation of incredibly widely used force-fields (FF) such as GROMOS/AMBER/OPLS and many more. Because of the assumptions ...
18
votes
1answer
486 views

How to optimize zinc oxide bulk structure at certain pressure with LAMMPS

I am trying to simulate the Zinc oxide bulk structure (periodic) at constant pressure(0.0 ~ 20.0 GPa) to observe phase transition with LAMMPS. However, I approached a problem that the fluctuating ...
14
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0answers
89 views

Generating interatomic potentials via force matching [closed]

I am trying to learn best practices for force matching ab initio molecular dynamics (AIMD) data with nonlinear least-squares minimization to generate interatomic potentials for use in classical MD. I ...
15
votes
1answer
161 views

Why do interaction potential parametrizations of bulk systems not work for corresponding nano-systems?

I am studying several thermodynamics properties of crystalline iron oxides ($\ce{Fe3O4}$, $\gamma-\ce{Fe2O3}$) in their solid phases by MD simulations. At the moment, I am facing many difficulties in ...
33
votes
2answers
455 views

Machine learning interatomic potentials for molecular dynamic simulations: are they good?

I know the general question of machine learning in computational chemistry has been already raised here: What is the current status of machine learning applied to materials or molecular systems? ...
35
votes
3answers
557 views

In molecular mechanics, how are van der Waals forces modelled?

In terms of energy, how are van der Waals forces modelled (are there formulas/laws that govern these)?