Valence Shell Electron Pair Repulsion (VSEPR) theory predicts a molecule's 3D shape from one simple idea: electron pairs around a central atom — whether shared in a bond or sitting alone — are all negatively charged, so they push each other as far apart as possible over the surface of an imaginary sphere. This simulation runs that repulsion live: every electron pair is a charged point that continuously repels every other pair until the system settles into the same geometries chemists use every day.
VSEPR theory, developed by Ronald Gillespie and Ronald Nyholm in the 1950s, needs no quantum mechanics to work — just Coulomb's law and geometry — yet it correctly predicts the shape of the vast majority of small molecules.
A live electron-pair repulsion simulator: choose how many bonding and lone pairs surround a central atom and watch them push apart on an invisible sphere until they settle into a real VSEPR molecular shape.
Every bonding and lone pair is simulated as a mutually repelling charge constrained to a sphere around the central atom. Lone pairs carry extra repulsive weight, so the simulation naturally compresses bond angles the same way real lone-pair repulsion does in molecules like water and ammonia.
Pick a preset molecule or set bonding/lone pair counts directly with the sliders. Toggle lone-pair lobes and the repulsion field lines, then drag to rotate and scroll to zoom around the settling geometry.
VSEPR theory predicts molecular shape from pure geometry and Coulomb repulsion — no quantum mechanics needed — yet it correctly forecasts the shape of the overwhelming majority of small molecules chemists study.