  Topological materials are renowned for their ability to harbor states
localized at their peripheries, such as surfaces, edges, and corners.
Accompanying these states, fractional charges appear on peripheral unit cells.
Recently, topologically bound states and fractional charges at disclinations of
crystalline defects have been theoretically predicted. This so-called
bulk-disclination correspondence has been experimentally confirmed in
artificial crystalline structures, such as microwave-circuit arrays and
photonic crystals. Here, we demonstrate an additive rule between the real-space
topological invariant $\mathbf{s}$ (related to the Burgers vector $\mathbf{B}$)
and the reciprocal-space topological invariant $\mathbf{p}$ (vectored Zak's
phase of bulk wave functions). The bound states and fractional charges concur
at a disclination center only if $\mathbf{s}+\mathbf{p}/2\pi$ is topologically
nontrivial; otherwise, no bound state forms even if fractional charges are
trapped. Besides the dissociation of fractional charges from bound states, the
additive rule also dictates the existence of half-bound states extending over
only half of a sample and ultra-stable bound states protected by both
real-space and reciprocal-space topologies. Our results add another dimension
to the ongoing study of topological matter and may germinate interesting
applications.
