Volume Change Associated with Noncubic Defects in a Monatomic Lattice

The formalism of the method of lattice statics is applied to obtain an expression for the volume change associated with a noncubic point defect in a monatomic lattice, assuming that the defect exerts no shear stress. This expression is used to calculate the volume changes associated with the octahedral and tetrahedral carbon interstitials in $\alpha$-iron.