  Predicting and directing polymorphic transformations is a critical challenge
in zeolite synthesis. Although interzeolite transformations enable selective
crystallization, their design lacks predictions to connect framework similarity
and experimental observations. Here, computational and theoretical tools are
combined to data-mine, analyze and explain interzeolite relations. It is
observed that building units are weak predictors of topology interconversion
and insufficient to explain intergrowth. By introducing a supercell-invariant
metric that compares crystal structures using graph theory, we show that
topotactic and reconstructive (diffusionless) transformations occur only
between graph-similar pairs. Furthermore, all known instances of intergrowth
occur between either structurally-similar or graph-similar frameworks. Backed
with exhaustive literature results, we identify promising pairs for realizing
novel diffusionless transformations and intergrowth. Hundreds of low-distance
pairs are identified among known zeolites, and thousands of hypothetical
frameworks are connected to known zeolites counterparts. The theory opens a
venue to understand and control zeolite polymorphism.
