Formation of dimethyl ether CH₃OCH₃ at 15 eV following the chemical pathways as a function of time. a: initial conditions. In color the projectile and methanol molecules that actively react. The remaning methanol molecules are represented by grey lines. They absorve some of the collision energy even though they do not break or form new chemical bonds. b: radical formation at 87.5 fs. c: radical-radical association at 164 fs. The colored OH and H₂O molecules escape the system.