# Equilibrium concentration of point defects in solids at sufficiently elevated temperature

Equilibrium concentration of point defects in solids is defined as $$\chi=\exp(\frac{\Delta s}{k_B})\exp(\frac{-\Delta h}{k_BT})$$. At high temperatures, may be even higher than melting temperature of the solid, does the entropy become undefined meaning there will be no equilibrium concentration for point defects?

• Why would the entropy become undefined? – Buck Thorn Apr 20 at 9:05
• Could you elaborate as to why you think entropy will become undefined. – A.K. Apr 20 at 15:21
• I was thinking may be at a high enough temperature, the number of microstates becomes infinite hence the $S=k_B \ln W$ becomes infinite/undefined? – ahmf Apr 20 at 17:11