Thank you very much Abraham for your EXTENSIVE and useful answer. Also Thanks Yun-Peng, it is an interesting software.
-Abbas On Thu, Sep 29, 2011 at 9:36 PM, Abraham Hmiel <[email protected]> wrote: > Hello Abbas, > > This is usually a multi-step process. At a general level, you need to look > at the quantities derived from orbital populations. Projected density of > states is an important one. If you use the pdos utility or a special script > you write, you can separate the PDOS data file into PDOS aggregated onto a > specific atom, group of atoms, orbital, or selected orbitals on selected > atoms. You should re-read the section in the manual about PDOS, how to > create it, etc. The other thing you can look at is the crystal orbital > overlap population by running the COOP utility mprop. Look elsewhere on the > list for information in how to set that data file, basically, you select > pairwise atoms/orbitals and a range of distances and it will calculate COOP. > You will have to manually prepare a lot of data and look at it side by side > to determine which orbitals are interacting strongly at what energies. > > From that, you can see a general energy range of where to look for the > local (spatial) electronic density of states (plotted with grid2cube), which > can be supplied as a range of energies in the fdf. The other way to do is is > to plot a lot of wavefunctions and use the denchar utility to make .cube > files then plot isosurfaces of the complex wavefunction at a particular grid > density using a program of your choosing. If you look at them side by side > in sequence, you can discern characteristics that mark the spatial patterns > of what you're looking for. Unfortunately, sometimes these visualization > files can get quite large and cumbersome for some computers to handle, but > either way you should then have a pretty good idea of "which band" since > they are numbered sequentially up from the lowest energy state. It's not > going to tell you "BEEP: THIS BAND IS PI*" but it is a judgment you will > have to make. > > And then have the band structure handy for reference & to put everything in > perspective. You should write a script or something that can identify an > energy band in the k-range you specify in a crystal. Combined, these things > are all ingredients of good convincing arguments in a publication. > > Best of luck, > > -- > Abraham Hmiel > Katherine Belz Groves Fellow in Nanoscience > Xue Group, College of Nanoscale Science and Engineering at SUNY Albany > > > On Thu, Sep 29, 2011 at 9:54 PM, Abbas Ebnonnasir < > [email protected]> wrote: > >> Dear SIESTA users, >> >> I'm trying to find out how I can identify each band in band structure >> plot, resulted from SIESTA, i.e, I need to know which band belongs to which >> molecular/crystal orbital (which one is Pi, which one is Pi*, Sigma....). >> >> Any comment will be appreciated. >> Thank you in advance. >> >> All the wishes, >> >> -Abbas >> >> >> > >
