Google has used its recording-breaking quantum computer to complete the biggest quantum chemistry simulation ever, modelling the behaviour of a long chain of hydrogen atoms.

Simulation of large molecules is one of the main expected applications of quantum computers in the near future. Such molecules are difficult to fully understand using classical computers – the largest we can simulate accurately is pentacene, which contains 22 carbon atoms and 12 hydrogen atoms, says Jamie Garcia at IBM. “As molecules get larger, they very quickly get out of the realm of what you can simulate …