In a solid lattice, the cation has left a lattice site and is located at interstitial position, the lattice defect is:

The Frenkel defect occurs when a cation in a solid lattice leaves a lattice site and is placed in an interstitial position. This flaw is seen in compounds with a low radius ratio and coordination number. In compounds with a strongly polarising cation and a readily polarisable anion, it can also be discovered.