Dear M Alaaii, I'm afraid your explanation of what you are doing is not clear enough for the collegues to help you; in particular you mention LDOS; projected wavefunction; moreover, a confusion might arise from "Siesta" definition of local density of states (i.e., space-resolved property) from the "conventional" one (energy-resolved property on specific atoms, i.e. Siesta's PDOS).
Having not much experience with interaces etc., I can only make a guess of what might be problematic. If you sum up all contributions (PDOS?) from all interface atoms, it can indeed include much more than purely interfacial states. First you have to identify the genuinely interface states, both on the energy scale (looking at PDOS and comparing it to that of pure Si and SiO2) as well as in space (looking at LDOS calculated in the selected energy window). This might be tricky because of overlap of these state with others. However, an attempt to isolate these states in both energy and spacial domains might give you the best you may probably achieve. Then, you interpolate the LDOS constructed in carefully selected energy interval onto the carefully selected spatial box that confines possibly clearly the interface states (using my rho2xsf script or other). Then, as you get the desired property of a selected 3-dim. grid, you can do with it whatever you want - sum up over Z and get it (X,Y)-resolved; sum it up over all box and attribute to surface unit, etc. Of course I don't know whether this will give a good agreement with expt., because you should look into what exactly the experiment measures. Its reported number is possibly also obtained in some indirect way... Best regards Andrei Postnikov > Dear All, > This is my second email and I highly appreciate your help in this regard. > I am working on Si/SiO2 system, at the moment. > > 1. I was wondering whether the sum of all LDOS calculated from projected > wavefunction on the Si at the interface can give me the density of > interface > states. The question is whether the sum of LDOS of projected > wavefunction > on > the inter-facial atoms is equivalent to planar local density of state at > the > interface. > 2. If positive, the sum of LDOS of all projected wavefunction on all > atoms at the interface divided by the surface of the interface is by far > higher than the Dit reported from experiment. Actually, I am thinking, > no > matter how big the structure is, the Dit is still very high. I was > wondering > whether I miss any point to consider for calculation. > > I really really appreciate your help. > Have a great summer. > M Alaaii >
