How to calculate the ionicity factor ?

To learn how to determine the ionicity factor qualitatively check the following article of Zaoui

https://materials-sciences-algerien1970.blogspot.com/2020/03/how-to-determine-ionicity-factor.html

Pr Rabah Riane had tried to do this calculation using Wien2k code as in the following article

Ab initio Calculations of Electronic Band Structure and Charge Densities of Zinc Blende-type GaN, BN and Their Solid Solution B0.5Ga0.5N


The ionicity factor

Three different approaches have been used to calculate the ionicity factor for GaN and BN:

(i) the model of Zaoui et al. based on valence charge density calculations [37],

(ii) the Pauling definition based on electronegativity values of the elements [38] 

and the

(iii) Garcia-Cohen approach based on valence charge density calculation [39].
The Zaoui ionicity factor is defined as follows [37]

(Eq. 2):  fI =[SA/(SA +λSC)]λ     (2)