This example shows how to calculate the Density of States (DOS) and how to plot the Fermi Surface of Ni.
The calculation proceeds as follows (for the meaning of the cited input variables see the appropriate INPUT_* file)
- make a self-consistent calculation for Ni (like in example 1). (input=ni.scf.in, output=ni.scf.out)
- make a band structure calculation for Ni (input=ni.dos.in, output=ni.dos.out) on a uniform k-point grid (automatically generated). In this example the Fermi level is calculated with the tetrahedra method (not in the actual band structure calculation but in the subsequent DOS calculation). If preferred, a gaussian broadening may be specified in this or in the subsequent step.
- the program dos.x reads file filpun (ni.pun) and calculates the DOS on a uniform grid of energies from Emin to Emax, with grid step Delta E. The output DOS is in file ni.dos, ready for plotting.
- the program projfwc.x projects the crystal wavefunctions on an orthogonalized basis set of atomic orbitals, calculates the Loewdin charges, spilling parameter, and the projected DOS (total DOS in file 'ni.pdos_tot', s and d component in files 'ni.pdos_atm#1(Ni)_wfc#1(s)' and 'ni.pdos_atm#1(Ni)_wfc#2(d)' respectively). (input=ni.pdos.in, output=ni.pdos.in)
- Fermi Surface plot (updated version of the tools by Eyvaz Isaev): make again a self-consistent calculation, followed by a non-scf calculation ('nscf') with tetrahedra (smearing is also OK as long as the Fermi energy s computed) and a dense automatic (Monkhorst-Pack) unshifted grid, using K_POINTS automatic 24 24 24 0 0 0 Finally, run the "fs.x" utility, specifying in namelist &fermi the correct "outdir" and "prefix", optionally the output filename "filfermi" and "DeltaE" (see below). The code will select bands that cross the Fermi energy Ef+/-1eV (or Ef+/-DeltaE if specified) and write them into file, "filfermi"_fs.bxsf for spin-unpolarized, "filfermi"_fsup.bxsf and "filfermi"_fsdw.bxsf for spin-polarized calculations (filfermi=prefix is not specified). Plot these files using "xcrysden --bxsf"
Quantum ESPRESSO is an integrated suite of computer codes for electronic-structure calculations and materials modeling at the nanoscale. It is based on density-functional theory, plane waves, and pseudopotentials. Quantum ESPRESSO has evolved into a distribution of independent and inter-operable codes. The Quantum ESPRESSO distribution consists of a “historical” core set of components, and a set of plug-ins that perform more advanced tasks, plus a number of third-party packages designed to be inter-operable with the core components.
For more details see Quantum Espresso .
Model New Results
Following are some related models available for cloning/copying by anyone: