Transition State Theory — 2D Reaction-Coordinate Landscape

This is the 2D counterpart to the 3D Eyring-equation simulator, computed independently rather than a flattened render of the 3D mesh. It draws the free-energy profile G(x) as a genuine side-on curve and integrates a real overdamped Langevin equation for every particle's reaction coordinate — the same stochastic-dynamics technique used in real molecular free-energy simulations — instead of a scripted per-particle success probability. The barrier height fed into that equation is exactly ΔG‡ = ΔH‡ − T·ΔS‡ from the sliders, so reshaping activation enthalpy, activation entropy or temperature reshapes the actual landscape every particle diffuses across. A scrolling strip beneath the landscape — a genuinely 2D-native view with no 3D equivalent — plots the reactant/product population split over time, while the reaction rate is measured directly as the net flux of particles crossing the dividing surface at the barrier top, the literal definition transition-state theory is built on.