states in chemical reactions ). Until as recently as 1956, however, there had not yet been calculations of a single molecule's properties on a computer . The first systematic study in 1956 on diatomic molecules (for example, N 2 ) was performed using Hartree-Fock theory at various basis sets . By 1971, the largest molecules computed were naphthalene and azulene . Even in the early 2000s, many works were published with a focus on comparing the energies and orbitals of a small number of molecules. This situation shifted drastically in the 2010s with the development of both quantum chemistry software packages and high-performance computing infrastructure , accelerating large-scale computation for chemistry simulation and advancing chemical discovery in catalysis and drug design .