Bulk matter
Liquids and gases as atoms in motion. This box is a real simulation running in your browser.
Molecule sandbox · Windows · v0.5.0
Chemistry that isn’t scripted.
Build molecules out of atoms, and watch bonds form and break on their own.
drag to rotate
| Water | Valence 0.5.0 | Measured |
|---|---|---|
| Angle | 105.0° | 104.5° |
| O–H | 1.003 Å | 0.958 Å +4.7 % |
| Charge on O | −0.55 e | computed |
Drawn live at the shape Valence 0.5.0 computes.
Five scales in 0.5.0
From a drop of liquid down to a quark.
Scroll to zoom. Drawn live in your browser; new work goes into the molecules.
Molecules in development
The sandbox: atoms competing for partners.
Atom
Electrons as clouds of probability, never as balls on orbits.
Nucleus
Six protons and six neutrons: the heart of a carbon atom.
Quarks
Inside one proton: three quarks bound by the strong force.
How it works
Every atom has a valence.
Atoms compete for bonding partners. Molecules are what that competition settles into.
01
Bonds form and break on their own
Reactions happen when the physics allows them.
02
Shapes aren’t looked up
Water bends and methane turns tetrahedral because of their electrons.
03
Every number is labelled
Each result says how far it is from measurement.
- Drag and shoot atoms
- Build molecules atom by atom
- Heat them up
- Make ions
- Save and pick up where you left off
Measured, not assumed
Checked against real molecules, misses included.
2.5%
average bond-length error against measured molecules
1,414
automated tests passing
0
molecules or reactions written into the code
Who’s building it
One founder, and Claude.
Built by Arda Yıldız, with Claude (Anthropic’s model, in Claude Code) as the main engineer. About the project