Subshells, atomic definition

The International Union of Pure and Applied Chemistry (lUPAC) defines transition elements as those whose atoms or ions have an incomplete d subshell. This definition excludes Zn, Cd, and Hg. The problem is discussed in more detail in Chapter 21. 

The definition of basis sets involves the selection of a set of functions for each angular momentum of the atom. In non-relativistic calculations, is a good quantum number, but in relativistic calculations it is j or k which is the good quantum number. However for the lighter elements where the effects of relativity are small, is an approximately good quantum number, and basis sets for the spin-orbit components of a non-relativistic subshell can share exponents. Basis sets that are optimized with the same exponents for the two spin-orbit components are called -optimized. Similarly, basis... 

Transition elements. How does the definition, Transition elements are those whose neutral atoms have partly filled d otf subshells differ from that given at the beginning of diis chapter Which definition includes more elements Name the elements covered only by the broader definition. 

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