ABSTRACT
Magnetism can arise both from localized and delocalized electrons. This chapter helps the reader to learn the basics of both types of magnetism. It begins with the atomic description. The resulting coordination chemistry dictates the ensuing chemical and physical properties, including magnetism. Before the chapter discuss the effect of atomic orbitals on the origins of magnetism, it is worthwhile to visualize the shape of the orbitals participating in the bonding process. The chapter considers the Zeeman interaction from the perspective of the quantum angular momentum. Spin-orbit interaction is an intrinsic effect generated by the interaction between spin and the orbital degrees of freedom of an electron. The size of the crystal field splitting plays a crucial role in distinguishing between two different magnetic ground states - high spin and low spin states of transition metal complexes. The heavier the element, the stronger is the spin-orbit coupling effect. The chapter explores the consequences of this statement on Hund’s rules.
