Reply to "Comment on 'Piezoelectricity in planar boron nitride via a geometric phase'"

In relation to our original paper [M. Droth et al., Phys. Rev. B 94, 075404 (2016)], the Comment by Li et al. [Phys. Rev. B 98, 167403 (2018)] claims to have identified a “mistake in constructing the adiabatic process of the piezoelectricity”. More specifically, they write that in our original work “the erroneous usage of the polarization difference formula in Eq. (4) leads to an invalid analytical expression of piezoelectric constant in Eq. (12) of Reference 1”. We explain below why these and other minor claims in the Comment are unwarranted, and why we maintain that our result is correct and physically sound.