In order to hide the connectivity in the list of vertex coordinates, there is a large amount (roughly 80% of the mif file) of redundant data. By converting this to a list of unique vertices and their adjacency matrix (or pairwise connections) the memory footprint (both RAM and disk) can be majorly reduced. Mif files are already huge and wavefunctions are only going to get bigger, potentially being able to email a top file is better.
In order to hide the connectivity in the list of vertex coordinates, there is a large amount (roughly 80% of the mif file) of redundant data. By converting this to a list of unique vertices and their adjacency matrix (or pairwise connections) the memory footprint (both RAM and disk) can be majorly reduced. Mif files are already huge and wavefunctions are only going to get bigger, potentially being able to email a top file is better.