  We study Kawamata log terminal singularities of full rank, i.e.,
$n$-dimensional klt singularities containing a large finite abelian group of
rank $n$ in its regional fundamental group. The main result of this article is
that klt singularities of full rank degenerate to cones over log crepant
equivalent toric quotient varieties. To establish the main theorem, we reduce
the proof to the study of Fano type varieties with large finite automorphisms
of full rank. We prove that such Fano type varieties are log crepant equivalent
toric. Furthermore, any such Fano variety of dimension $n$ contains an open
affine subset isomorphic to $\mathbb{G}_m^n$. As a first application, we study
complements on klt singularities of full rank. As a second application, we
study dual complexes of log Calabi-Yau structures on Fano type varieties with
large fundamental group of their smooth locus.
