Plasma oscillations theory of solids has been used to calculate static χ⁽²⁾${\chi }^{(2)}$.

${\chi }_{123}^{(2)}(0)$ of zincblende II–VI and III–V semiconductors have been calculated.

${\chi }_{123}^{(2)}(0)$ of BeS, BeSe and BeTe have been calculated for the first time.

The calculated values are in good agreement with the experimental values.

The theory may be used to predict the value of χ⁽²⁾${\chi }^{(2)}$ of new binaries of same groups.