Ch 2.1 The complex-valued function $\psi(x, t)$ (or $\Psi(\mathbf{r}, t)$ in 3D) that encodes the complete quantum state of a particle. $|\psi(x,t)|^2$ gives the probability density for finding the particle at position $x$ at time $t$. In Dirac notation, $\psi(x,t) = \langle x|\psi(t)\rangle$. *See