The Free-Electron Model: From Otto Schmidt to John Platt

摘要

This paper outlines the historical development of the free-electron model of chemical bonding and spectra as a representative example of attempts by quantum chemists, in the period 1935-1965, to develop, in lieu of effective computerized computations, approximate "pen and paper" models of both chemical bonding and spectra. Beginning in 1938 with the pioneering work of Otto Schmidt, the history of the free-electron model is traced through the 1960s, with emphasis on the work of Hans Kuhn in Switzerland and John Platt and associates at the University of Chicago. It concludes with a brief evaluation of the continuing pedagogical relvance of the model.