This work characterizes the class of graphs for which the core equals the nucleus—that is, graphs where the intersection of all maximum independent sets coincides with that of all maximum critical independent sets. Building upon Larson’s independence decomposition, the graph is partitioned into a König–Egerváry part and a 2-bicritical part. By analyzing the boundary between these components and the structure of the corona, the study establishes, for the first time, a complete necessary and sufficient condition for core(G) = nucleus(G): the core of the 2-bicritical component must be empty, and no vertex of the corona may lie on the decomposition boundary. This condition is equivalent to diadem(G) = corona(G) ∩ L(G), offering deeper insight into the structural properties of independent sets and yielding several structural corollaries.