Configuration state function

In quantum chemistry, a configuration state function, or CSF, is a [[[Slater determinant]], representing an approximate electronic wavefunction within a molecule. The CSF can represent either an approximate ground state electronic configuration, or an excited state electronic configuration. In post-Hartree-Fock methods, CSFs are often used with coefficients to form linear combinations of CSFs, in order to approximate the effect of electron correlation within the molecule.