  We calculate single-neutron spectroscopic overlaps for lithium isotopes in
the framework of the \textit{ab initio} symmetry-adapted no-core shell model.
We report the associated neutron-nucleus asymptotic normalization coefficients
(ANCs) and spectroscopic factors (SFs) that are important ingredients in many
reaction cross section calculations. While spectroscopic factors have been
traditionally extracted from experimental cross sections, their sensitivity on
the type of reactions, energy, and the underlying models point to the need for
determining SF from first-principle structure considerations. As illustrative
examples, we present $^6$Li+n, $^7$Li+n, and $^8$Li+n, and we show that the
results are in a good agreement with those of other \textit{ab initio} methods,
where available, including the quantum Monte Carlo approach. We compare ANCs
and SFs to available experimentally deduced values, with a view toward
expanding this study to heavier nuclei and to extracting inter-cluster
effective interactions for input into analyses of existing and future
experimental data.
