An efficient method for determining zeolite vertex symbols

We present an efficient method for computing the topological vertex symbols of zeolite frameworks. The algorithm gets its efficiency by dividing the problem into a sequence of quickly executed breadth-first searches. For small rings (fewer than eight vertices), we find there is no speed gain compared with a distance table approach, both methods executing quickly. The main benefits occur for large rings, or when no ring exists, a situation that forces a fruitless search over the full model domain. In this situation, our method is typically 60 times faster.