  The present paper is devoted to the study of Keller admissible triples. We
prove that a Keller admissible triple induces an isomorphism of Gerstenhaber
algebras between the Hochschild cohomologies of direct-sum type of the pair of
differential graded algebras bound to one another by the admissible triple. As
an application, we give a new concrete proof of the Duflo--Kontsevich theorem
for finite-dimensional Lie algebras.
