In the 1920s, who created the Left-Step Periodic Table (LSPT) of the chemical elements, basing the positions of the elements on patterns in the arrangement of electrons around the atomic nucleus?

In 1928, the French engineer and polymath Charles Janet created the Left-Step Periodic Table (LSPT). It arranges chemical elements logically based on the filling of electronic orbital shells (s,p,d,f) in reverse order, placing the s-block elements on the far right (or left-step) and grouping elements continuously by their quantum numbers.