[Pw_forum] Band Gap Significance

[Luke Thulin]

Hello everyone,

As I understand it, DFT has a known inability to predict the band gap 
properly compared to measured values.  I have observed for the material 
I am currently studying.  Is the calculated value of no physical 
significance?  Or would relative values be valid, if for example, I 
wanted to calculate the percent change in band gap due to stress?

Thank you,
Luke