On the Bragg, Leibfried, and modified Leibfried numbers

The Bragg, Leibfried, and modified Leibfried numbers are defined in the con text of a theory of dislocation-mediated melting, and their values are dete rmined from the properties of the dislocation ensemble at the melting tempe rature. The approximate numerical coincidence of the Bragg and modified Lei bfried numbers is explained. The parameter K in the definition of the modif ied Leibfried number is shown to be the natural logarithm of the effective coordination number. Our analysis reveals that the Bragg number can be cons idered an elemental constant, in contrast to the Leibfried and modified Lei bfried numbers. (C) 2001 Elsevier Science Ltd. All rights reserved.