Quantum chemistry American approach

Despite participants assessments as stated above, differences in styles played a role in the early developments of quantum chemistry not only in what was referred to as differences between the Heitler-London school and the molecular orbital school but, more dramatically, in what related to the contrast between physically oriented approaches of German physicists and chemically oriented approaches of American scientists. Geographical differences were after all a subsidiary manifestation of strong differences in the institutional settings that provided the educational backgrounds of members of future quantum chemical communities. 

The publication of the papers by the Americans and especially those by Slater, Pauling, Van Vleck, and Mulliken prompted a rather desperate exchange of letters between Heitler and London starting in the end of 1935. This correspondence is quite revealing. It shows the attitude of each about the possible development of the approach laid down in their common paper, the tension between them, as well as the search for a means to consolidate their theory at a time when the Americans appeared to be taking over the field of quantum chemistry. The correspondence reflects the different style of their respective environments. Faithful to the Gottingen spirit, Heitler was... 

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