Structchord
\[D_{Structchord} = \sqrt{ \sum_{j=1}^{S_T} \left ( \frac{S_{Aj}}{\sqrt{\sum_{j=1}^{S_T} S_{Aj}^2 }} - \frac{S_{Bj}}{\sqrt{\sum_{j=1}^{S_T} S_{Bj}^2}} \right )^2 }\]- where \(S_{Aj}\) is the abundance of sample A in the jth OTU.
- where \(S_{Bj}\) is the abundance of sample B in the jth OTU.