One hundred years after its formulation, the Schrödinger equation remains the foundation of molecular quantum mechanics. Although the equation is conceptually simple, its application to more than one electron is not. Strongly correlated systems and electronically excited states — even in stationary states — are practically more difficult to describe and often require highly structured, multi-determinantal wavefunctions. This is particularly evident in open-shell systems, where Nature resists a simple one-determinant description and requires entangled, multi-reference wavefunctions. In this lecture, I will show how different pictures of molecular behavior — from stationary states to potential-energy surfaces and time-dependent nuclear motion — can now be captured with modern computational methods, using Fe(III) compounds as illustrative examples.