On the Complexity of Square-CeH Configurations*

Recent interest in square-cell configurations in chemistry+" prompted the present report. The name used for these configurations in discrete mathematics is square animals." A square-cell configuration is made up of square s which are simplyor multiply-connected.š It starts with asingle square and grows by adding squares, one at a time, in such amanner that the new square has at least one side in contact with a side of a square already present in the square-cell configuration. A square-cell configuration is simply-connected if it does not posses a hole, while the multiply-connected square-cell configuration is a configuration with holets). In Figure 1, a simply-connected square-cell configuration with nine squares is given as an example.