In 1935 J.H. de Boer gave a scientific presentation in England. He had been applying recent discoveries in the understanding of interatomic forces to the study of the cohesive properties of molecular crystals, the strength or inorganic materials, and the conformational analysis of polystyrene. In 1936 de Boer's paper, a forerunner of modern atomistic simulation studies, was published (see.), and it fascinating to see that after de Boer's talk, Professor Lennard-Jones remarked:
'While I agree that Van der Waals fields play an important role in the phenomena discussed by Dr. de Boer and that it is very desirable to estimate their magnitude, I should like to ask the author whether he thinks the theory sufficiently developed at present to make reliable quantitative calculations. I think the formula given by London was intended only for spherically symmetrical systems and even then it is only approximate. While it gives the right order of magnitude for the inert gases, it is not yet certain that there is not an error by a factor of two. But the error may he greater in the case of aromatic molecules owing to their lack of symmetry and to their special electronic structure in that they contain "non-localized" electrons. Is it not likely that these will require special treatment?
de Boer replied to Lennard-Jones that comparison between experiment and theory provided justification for the approach. A nice pragmatic response from one of the earliest practitioners of materials science atomistic simulation.
One cannot help but think that Professor Lennard-Jones might be surprised to learn today that many scientists now blithely trust potential descriptions of the types employed by de Boer without a second thought, and that frequently these potentials bear the name 'Lennard-Jones'....and, additionally, reliability of these potentials has been shown to be substantially better than Lennard-Jones feared.