  The fully-charm and -bottom pentaquarks, \emph{i.e.} $cccc\bar{c}$ and
$bbbb\bar{b}$, with spin-parity quantum numbers $J^P=\frac{1}{2}^-$,
$\frac{3}{2}^-$ and $\frac{5}{2}^-$, are investigated within a Lattice-QCD
inspired quark model, which has already successfully described the recently
announced fully-charm tetraquark candidate $X(6900)$, and has also predicted
several other fully-heavy tetraquarks. A powerful computational technique,
based on the Gaussian expansion method combined with a complex-scaling range
approach, is employed to predict, and distinguish, bound, resonance and
scattering states of the mentioned five-body system. Both baryon-meson and
diquark-diquark-antiquark configurations, along with all of their possible
color channels are comprehensively considered. Narrow resonances are obtained
in each spin-parity channel for the fully-charm and -bottom systems. Moreover,
most of them seems to be compact multiquarks whose wave-functions are dominated
by either hidden-color baryon-meson or diquark-diquark-antiquark structure, or
by the coupling between them.
