Tag Archives: DOS

sum_states.py: Nice DOS plots from QE outputs

Once, I was making some DOS figures with quantum espresso by using the sumpdos.x program by Andrea Ferretti (included in the QE package), but I felt that I am missing some features. Thereby, I wrote my own script, which does something similar, but it is much more automatized, it is faster to use, and it even produces ready-to-publish graphs automatically.

It is part of the quantum espresso distribution, so if you have the source code of quantum espresso, you have it in the …/*espresso*/PP/tools/sum_states.py. If you don’t have it, or you just want to read the source-code online, you can check for sum_states.py in the quantum espresso repository. Continue reading

dos-ipr.f: Calculate DOS and IPR with CPMD

The Denstiy OStates (DOS) and the Inverse Partitipation Ratio (IPR) are two interesting properties for understanding the electronic structure of a system.

The DOS is just a histogram counting the amount of states (molecular orbitals/wavefunctions) per energy unit, and analyzing these distributions, we can understand better the electronic behavior of our system.

The IPR is a way to analyze the “amount of localization” of these states, so that the larger the value of IPR the higher the localization around an specific covalent bond.

We used these two properties in an article published in Phys. Rev. B, named “Polymorphism in phase-change materials: melt-quenched and as-deposited amorphous structures in Ge2Sb2Te5 from“, which you can check for more information.  Continue reading