  In this work we propose possible quantum numbers of X(6900) and suggest a
model for it internal structure that explains its unusually high mass. We solve
the Schr\"odinger Equation with Mathematica 12, first for charmonium spectrum,
then for all-charm tetraquark spectrum which is understood as a pair of
two-particle states, mesons or diquark-antidiquark states. The obtained
candidates for all-charm tetraquark will be separated into contributors to
various resonances and structures that are visible in the experiments then an
explanation for the prominence of X(6900) will be proposed.
