CPU and Memory Requirements

The X-PLOR/DG code is highly vectorizable and parallelizable and should perform efficiently on most modern computer architectures.

The complexity of full metrization is ${\cal O} (N_{atoms}^{3})$, where $N_{atoms}$ is the number of atoms in the (sub) structure. The complexity of bound smoothing alone depends on the number of atoms and on the number of connectivities (known distances) in the molecule. For a molecule consisting of 500 atoms, it takes about 300s on a CONVEX 210 to embed the molecule using partial (4-atom) random metrization.

The X-PLOR/DG module allocates about $N_{atoms} \times N_{atoms}$ single precision words of memory. (Section 38.11 contains more CPU timing results.)