Crowdions in atomic cryocrystals and metals with fcc and bcc lattices

Numerical values are obtained for the parameters of the crystal-field poten tials and crowdions (self-energy, effective mass, characteristic length) fo r Ar and Kr fcc cryocrystals, Cu and Al fcc metals, and alpha- and delta -F e bcc metals. The calculations are performed assuming that the interatomic interaction in the crystals can be described by empirical Lenard-Jones and Morse pair potentials. A new algorithm is developed and used for calculatin g the crystal-field potentials. The algorithm is based on a representation of the crystal lattice as a collection of parallel atomic rows. An analytic expression in the form of a trigonometric series is obtained for the poten tial describing the interaction between an atom in a close-packed row and t he crystal matrix. An explicit analytic expression is also obtained for the energy parameter characterizing the interatomic interaction inside a disti nguished row. It is shown that the main condition for weak coupling between close-packed rows and the crystal matrix, admitting the existence of crowd ions and the application of the long-wave approximation for describing crow dions, is satisfied in all crystals investigated. (C) 2001 American Institu te of Physics.