I am studying the associating schemes proposed by De Villiers et al. (DOI:10.1021/ie200521k) in 2011.
In order to give their analytical expression for XA (the non-bonded site fraction) they establish the relation between the fractions of XA and XB as:
XB= (XA)^1/2
However, I wish to understand how did they reached the conclusion that this was the relationship between the two, as in the publication it is mentioned but not clearly demonstrated.