Yambo Community Forum

Hi
I'm trying to plot the exciton, I noticed that there are paper which is fixed the hole at the top of atom, as the case in boron nitride paper (Huge Excitonic Effects in Layered Hexagonal Boron Nitride PhysRevLett.96.026402) the hole located above a nitrogen atom
I want to know what is difference between the hole position fixed on atom-atom bond (above the bond) and top position hole (top of atome) ?

Dear Fatima,
the excitonic wave function depends on both hole and electron positions. The position of the hole is arbitrary, in order to have insight from the exciton wavefunction it is useful to fix the hole in a symmetric position (if any) or anyway in a part of the space where you have a big hole density, ie, look at the weights of your excitations and see where you have a big density in the occupied orbitals that participate in that excitation.

Best,
Daniele

Dr Daniele
Thanks for your quick and clear reply. I understand now.