Schroedinger&#x27;s theory of hydrogen atom and his wave mechanics (1926). It explained positions of emission lines of excited hydrogen, but it didn&#x27;t explain how the atoms lose excitation energy as there is no <i>c</i> and no spontaneous emission in that theory. Larmor&#x27;s older theory (1897) explained how the energy is lost - by EM radiation - and gave formula connecting acceleration and losses that is used to this day.<p>Joseph Larmor, LXIII, <i>On the theory of the Magnetic Influence on Spectra ; 
and on the Radiation from moving Ions</i>, Philosophical Magazine Series 5 
Vol. 44, Iss. 271, 1897<p>Erwin Schrodinger, <i>Quantisierung als Eigenwertproblem</i>. Annalen der Phys. 384 (4) (1926)