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Manuscript Title: Harmonic Debye-Waller factors for cubic materials.
Authors: J.S. Reid
Program title: DWB87
Catalogue identifier: AATZ_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 46(1987)141
Programming language: Fortran.
Computer: HONEYWELL 66/80.
Operating system: GC0S8.
RAM: 38K words
Word size: 36
Keywords: Debye-Waller factors, Mean square, Vibrational amplitudes, Cubic materials, NACL structure, Diamond structure, Zincblende structure, Solid state physics, Lattice dynamics.
Classification: 7.8.

Nature of problem:
Determination of the Deybe-Waller B factors (which are proportional to the mean square vibrational amplitudes of atoms) at any temperature using lattice dynamical eigendata. Also, for a shell model, to determine the X-ray Debye-Waller B values appropriate to motion of the shell.

Solution method:
The Brillouin zone is covered by a lattice of 8n**3 points, where there are n points from origin to zone boundary along [100]. The analytic expression for the B value for each atom is evaluated from a minimum set of eigendata for the range of temperatures in the input list.

Restrictions:
As supplied, the program is written for a face-centred-cubic material with any number of atoms per primitive unit cell; output format modifications are necessary if the number of atoms exceeds 8. Body- centred-cubic and simple cubic materials are handled by the replacement of one routine.

Running time:
Depends on n**3. About 12 s for 26 temperatures, with n=10 and 2 atoms per unit cell.