by 1926, he was assigning atomic term symbols, such as and individual " electron quantum numbers", such as s, p, and d, to diatomics based on those of the corresponding hypothetical united atom. By 1928, he had further refined his symbolism for the molecular quantum numbers of individual electron in the and was talking instead of configurations,and so forth, where, for example, referred to an electron in the diatomic corresponding to an electron in the united atom with the quantum numbers