Ch 15.4 An antisymmetrized product state for $N$ fermions: $\psi(\mathbf{r}_1,\ldots,\mathbf{r}_N) = \frac{1}{\sqrt{N!}}\det[\phi_i(\mathbf{r}_j)]$. Automatically satisfies the Pauli exclusion principle. The starting point for the Hartree-Fock method. *See also:* Fermion, Pauli exclusion principle,