The morphology of Beta-16.16.16, Beta-10.12.10, and Beta-16.16.14 fat
crystals is explained on the basis of a connected net analysis taking into
account the edge energies of a 2D nucleation growth mechanism. It is shown
that the conventional prediction of the morphology on the basis of attachment
energies is not capable of explaining the very different morphologies of
these fat crystals. The morphology of the three fats ranges from long needles
in spherulitic growth forms to lozenge shaped single crystals. It is shown
that the elongated growth habit of '-10.12.10 fat crystals having fast
growing top faces is a result of a very small edge free energy of 2D nuclei
on these faces. The bonding topology and its high structural symmetry explain
these small edge energies. In contrast, for the '-16.16.14 crystals, having
a lower symmetry, the corresponding edge energies are much higher, resulting
in lozenge shaped crystals