Finding the concentrations of vacancies and interstitials

[Tom Weaver]

Consider a two-dimensional ionic crystal with a primitive hexagonal lattice. The energy needed to create a Frenkel defect pair is 10eV, and Schottky defect formation costs 8eV.
Calculate the concentration of vacancies and interstitials in the crystal at 300 K, assuming that all defects are intrinsic.

n/N=e^{-(E_def/k_bT)}
Where: n = number of defects
N = number of atoms in the crystal
E_def = defect creation energy
k_b = Boltzman's constant
T = temperature

I've tried using 10eV and 8eV as the defect creation energy however this equals to an answer smaller than *10^-100, unsure how to progress.

Thanks in advance!

 

[mfb]

That is correct. The equilibrium concentration for those defects at room temperature is effectively zero.

Why do we still have those defects in crystals?