  A balanced description of ground and excited states is essential for the
description of many chemical processes. However, few methods can handle cases
where static correlation is present, and often these scale very unfavourably
with system size. Recently, multiple Hartree--Fock (HF) solutions have been
proposed as a basis for non-orthogonal configuration interaction (NOCI) to
provide multireference ground and excited state energies, although applications
across multiple geometries have been limited by the coalescence of HF
solutions. Holomorphic HF (h-HF) theory allows solutions to be analytically
continued beyond the Coulson--Fischer points at which they vanish but, until
now, this has only been demonstrated for small model systems. In this work, we
propose a general protocol for computing NOCI ground and excited state energies
using multiple HF solutions. To do so, we outline an active space variation of
SCF metadynamics that allows a chemically relevant set of HF states to be
identified, and describe how these states can be routinely traced across all
molecular geometries by exploiting the topology of h-HF solutions in the
complex plane. Finally, we illustrate our approach using the dissociation of
the fluorine dimer and the pseudo-Jahn--Teller distortion of cyclobutadiene,
demonstrating its applicability for multireference ground and excited states.
