DMC is a stochastic method that solves the Schrödinger equation using random sampling techniques. It involves representing the wave function of a system as a distribution of "walkers" (particles) that evolve over time according to certain rules. These walkers diffuse, branch, and die in a manner that eventually leads to the ground state energy of the system. DMC is particularly known for its ability to treat electron correlation effects accurately, which is crucial in complex catalytic systems.