Composite Methods in Quantum Chemistry
“A cord of three strands is not easily broken.” —Ecclesiastes 4:12Abu Simbel relief of Ramesses II shooting a composite bow at the Battle of Kadesh. Computational chemistry, like all attempts to simulate reality, is defined by tradeoffs. Reality is far too complex to simulate perfectly, and so scientists have developed a plethora of approximations, each of which reduces both the cost (i.e. time) and the accuracy of the simulation.