Calculate surface roughness. In the case of a cylindrical pore one can visualize pulling the pore apart, thus flattening the interior surface. The roughness is then determined by calculating the standard deviation of the binding site silicon atoms peaks and valleys.
It is therefore enough to calculate the distances towards a specific axis, which in this case will be the central axis. The mean value \(\bar r\) of the silicon distances \(r_i\) of silicon \(i\) towards the pore center, is calculated by
with the number of silicon atoms \(n\). This mean value is used in the square root roughness calculation
Surface roughness