Understanding Semi-Core Bands in Group-III Nitrides

[akinokoe]

Hi friends,

I am currently reading a review of band-structure calculation of group-III nitrides. I got stuck at 'Of importance is that the Local Density Approximation(LDA) method can handle the overlapping between the Ga 3d semi-core bands with the N 2s bands, which leads to two separate bands.' What does this 'semi-core bands' mean?

Thank you.

 

[olgranpappy]

I think they might just mean that those bands are flatter than the others which makes them similar to deep core electrons (which have nearly no dispersion).