Self-trapped particles in crystals

I have also participated in theoretical investigations of the self-trapped (ST) phenomena in ionic crystals. The general problem is that the total energies of two completely different states, namely delocalised free particle and well localised ST states, must be compared in order to address the question of whether the particle is self-trapped or not. In [B30], preliminary calculations of the hole ST energy in the KCl crystal have been reported based mainly on a number of intuitive arguments. In [B33,B36] a general approach to the problem has been suggested. The method is based on a set of intermediate steps along an artificial path "free state - ST state". Then, using different methods for calculating the energy differences between any sequential points along the path, the ST energy is calculated. Actual calculations have been done for the KCl crystal [B33,B35] and corundum [B36].
 

7/2/1999