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AtomCentered

This page gives hints on how to compute atom-centered properties like the integral of the charge within a sphere, or orbital magnetization within a sphere, etc, with the ABINIT package.

Introduction

For the purpose of understanding a material, it is interesting to be able to integrate the density, the spin-magnetization, or the orbital magnetization in a sphere around an atom. Also, taking into account only s-, p-, or d- contributions might be desirable.

The definition of the list of atoms and the radii of the spheres is made through natsph, iatsph and ratsph, and apply to all such sphere-based calculations. In the PAW case, ratsph is the PAW sphere cut-off from the PAW atomic dataset, but can be adjusted in the NC case. It is even possible to define spheres that are not centered on an atom, using the inptut variables natsph_extra, xredsph_extra and ratsph_extra.

The computed integrated charges or magnetizations are printed inside the main output file of ABINIT.

For the DOS, use the intput variable prtdos with value 3 or 4, possibly m-decomposed if prtdosm is activated. In the PAW case, use pawprtdos.

To perform an atom-by-atom orbital magnetization integration inside the PAW spheres, use the prt_lorbmag input variable.

A band structure can even be represented using weights proportional to the orbital content (so-called “Fat Bands”), in case of PAW calculation, see pawfatbnd, and related variables.

This topic is also strongly related to the two topics topic_ConstrainedDFT and topic_MagMom.

compulsory:

  • iatsph Index for the ATomic SPHeres of the atom-projected density-of-states
  • natsph Number of ATomic SPHeres for the atom-projected density-of-states
  • natsph_extra Number of ATomic SPHeres for the l-projected density-of-states in EXTRA set

basic:

  • ratsph Radii of the ATomic SPHere(s)

useful:

  • pawfatbnd PAW: print band structure in the FAT-BaND representation
  • pawprtdos PAW: PRinT partial DOS contributions
  • prt_lorbmag PRinT L ORBital MAGnetic moment inside PAW spheres
  • prtdos PRinT the Density Of States
  • prtdosm PRinT the Density Of States with M decomposition
  • ratsph_extra Radii of the ATomic SPHere(s) in the EXTRA set
  • xredsph_extra X(position) in REDuced coordinates of the SPHeres for dos projection in the EXTRA set

Selected Input Files

tutorial:

v4:

v5:

v9: