Computers and molecular quantum mechanics: 1965-2001, a personal perspective

From the earliest days of electronic computers, molecular electronic struct ure theorists have been among the most demanding of users, both in terms of raw cpu power and machine sophistication. Here we describe both computer h ardware and theoretical chemistry methods developments during what may be c alled the second and third ages of quantum chemistry. These developments ex tend the applicability of molecular quantum mechanics to most fields of che mistry. The 'One Percent Rule' predicts that 1% of chemical research will m igrate each year from experiment to computation for the foreseeable future. This rule, put forth by the author in December 1995 at the International C ongress of Pacific Basin Societies in Honolulu, has exceeded expectations o ver the first six years of its existence. (C) 2001 Elsevier Science B.V, Al l lights reserved.