  We present an ab initio symmetry-adapted no-core shell-model description for
$^{6}$Li. We study the structure of the ground state of $^{6}$Li and the impact
of the symmetry-guided space selection on the charge density components for
this state in momentum space, including the effect of higher shells. We
accomplish this by investigating the electron scattering charge form factor for
momentum transfers up to $q \sim 4$ fm$^{-1}$. We demonstrate that this
symmetry-adapted framework can achieve significantly reduced dimensions for
equivalent large shell-model spaces while retaining the accuracy of the form
factor for any momentum transfer. These new results confirm the previous
outcomes for selected spectroscopy observables in light nuclei, such as binding
energies, excitation energies, electromagnetic moments, E2 and M1 reduced
transition probabilities, as well as point-nucleon matter rms radii.
