  This is the second contribution in a series of papers dealing with dynamical
models in equilibrium theories of polytypism. A Hamiltonian introduced by Ahmad
avoids the unphysical assignment of interaction terms to fictitious entities
given by spins in the Hagg coding of the stacking arrangement. In this paper an
analysis of polytype generation and disorder in close packed structure is made
for such Hamiltonian. Results are compared with a previous analysis using the
Ising model. Computational mechanics is the framework under which the analysis
is performed. The competing effects of disorder and structure, as given by
entropy density and excess entropy, respectively, is discussed. It is argued
that the Ahmad and Khan model is simpler and predicts a larger set of polytypes
than previous treatments.
