First published in 1919, it became the Bible of atomic physics, and its successive editions, appearing almost annually in the early 1920s, chronicled the progress of this field up to the eve of the introduction of quantum mechanics. In these years, 1919-1926, Sommerfeld remained in the forefront of theoretical atomic physics; but he did so largely by reorienting his method and approach. He pioneered a new style of theoretical spectroscopy.

Although not among the inventory of quantum mechanics, of quantum statistics, or of electron spin, Sommerfeld immediately became one of the most adept in the exploitation of these new concepts and prescriptions for the calculation of energies and rates of atomic processes, and the macroscopic properties of matter resulting from them. It was Scrodinger's form, the wave mechanics, the partial differential equation, that Sommerfeld found the most congenial.

Sommerfeld, who had been responsible for extending the Bohr atomic theory to include elliptic orbits, brought together in his book all the materials then known to pertain to atomic structure as revealed by spectroscopic evidence. In the years before 1925 it held a unique place as a reference book as well as a text.