PPolySim OS

Molecular Dynamics Simulator

Atoms attract and repel through a Lennard-Jones potential. Raise the temperature and watch an ordered lattice melt into a liquid, then a gas.

Molecular Dynamics StudioLive

Controls

Atoms interact via a Lennard-Jones potential. Raise the temperature to melt the lattice.

Presets

▶ Run in Python

Data Inspector

Atoms120
Temperature0.0
PotentialLennard-Jones
IntegratorVelocity-Verlet

Governing equation

Reading this result: Near a target of 120, thermal energy rivals the Lennard-Jones well depth, so the 120-atom lattice loses its order and begins to flow — melting.

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How it works

Each pair of atoms interacts via the Lennard-Jones 12-6 potential, integrated with velocity-Verlet in a periodic box using the minimum-image convention. A velocity-rescaling thermostat holds the target temperature. This is the same method used to study diffusion, phase transitions, and material properties from first principles.

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Frequently asked questions

Is this molecular dynamics tool really free?
Yes. Molecular Dynamics Simulator runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.
Do I need to install anything?
No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.
Can I save or share my simulation?
Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.
How accurate are the results?
The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.