PACK program computational analysis

Table I (taken from Martin, Sykes, and Hioe16) contains the most recent exact enumerations of C for the triangular and fee lattices. Similar enumerations for other lattices have been given elsewhere ° 11 numerical analysis indicates that the close packed lattices lead to most rapid convergence, and these were therefore selected for an extensive enumeration project. It should be noted that C12 for the fee lattice is of order 1.8 x 1012. Using a direct enumeration procedure on a digital computer, the machine time required would be quite prohibitive. It is only by the way of sophisticated counting theorems17 and skilled programming that these numbers could be obtained.

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