QE is a suite, not one program. This is the map of what each executable
takes and produces. Per-variable detail lives in each code's
Doc/INPUT_<name>.txt.
The core pipeline
| Executable | Input namelists | Prerequisite | Products | Chapter |
|---|---|---|---|---|
pw.x |
&CONTROL+&SYSTEM+&ELECTRONS (+&IONS, &CELL) |
none | Total energy, forces, stress, density, wavefunctions | 02 |
dos.x |
&DOS |
nscf | Total DOS (fildos) |
10 |
projwfc.x |
&PROJWFC |
nscf | PDOS, Löwdin charges | 10 |
bands.x |
&BANDS |
calculation='bands' |
Band data (.gnu), symmetry labels |
10 |
pp.x |
&INPUTPP + &PLOT |
scf | Densities, potentials, ELF (cube/XSF) | 11 |
average.x |
(free-format input) | pp.x | Planar averages (work function) | 15 |
hp.x |
&INPUTHP |
scf + HUBBARD card | Hubbard U and V (*.Hubbard_parameters.dat) |
14 |
ph.x |
&INPUTPH |
scf | Dynamical matrices (fildyn) |
17 |
q2r.x / matdyn.x |
own formats | ph.x | Real-space force constants / phonon dispersion and DOS | 17 |
neb.x |
&PATH + engine input |
both endpoints optimized | Minimum-energy path, barrier | 17 |
cp.x |
separate CP input | none | Car-Parrinello MD | see 16 |
pw2wannier90.x |
&INPUTPP |
nscf + Wannier90 | Wannier interface files | 17 |
plotband.x |
interactive | bands.x | Band-plot data | 10 |
Post-processing namelists in brief
dos.x: &DOS
prefix, outdir, fildos, Emin, Emax, DeltaE, ngauss,
degauss, bz_sum. The output columns are E (eV), DOS (two spin columns
in polarized runs), and the integrated DOS. Note that Emin/Emax are
absolute energies in eV; place the window around the actual Fermi level
of your system, which for PAW data can sit at 15–20 eV.
projwfc.x: &PROJWFC
prefix, outdir, filpdos, filproj, ngauss, degauss, Emin,
Emax, DeltaE, lsym (symmetrized atomic orbitals), pawproj,
lwrite_overlaps, kresolveddos. Outputs the
filpdos.pdos_atm#N(label)_wfc#M(orbital) files plus the Löwdin
charges block on standard output.
bands.x: &BANDS
prefix, outdir, filband, lsym (assign symmetry labels),
spin_component, lp (momentum matrix elements). filband.gnu is the
plottable file, and the high-symmetry point lines on standard output give
the tick positions.
pp.x: &INPUTPP + &PLOT
&INPUTPP: prefix, outdir, filplot, plot_num, spin_component,
sample_bias, kpoint, kband.
plot_num |
Quantity |
|---|---|
| 0 | Valence charge density |
| 1 | Total potential (V_bare + V_H + V_xc) |
| 2 | Local ionic potential |
| 5 | STM image |
| 6 | Spin density ρ↑ − ρ↓ |
| 8 | ELF |
| 11 | Bare + Hartree potential (work function) |
&PLOT: nfile, filepp(i), weight(i), iflag (0 line / 1 spherical
average / 2 plane / 3 3D / 4 polar), output_format (0 gnuplot /
3 XCrySDen 2D / 5 XSF 3D / 6 Gaussian cube / 7 gnuplot 2D), fileout,
e1,e2,e3, x0, nx,ny,nz. PAW all-electron options vary by version;
check Doc/INPUT_PP.txt.
hp.x: &INPUTHP
prefix, outdir, nq1/nq2/nq3, conv_thr_chi, thresh_init,
iverbosity, start_q/last_q (job splitting), perturb_only_atom(i),
skip_equivalence_q, determine_num_pert_only, compute_hp (assemble
partial results).
ph.x: &INPUTPH
prefix, outdir, fildyn, tr2_ph, ldisp, nq1/nq2/nq3, epsil,
zeu, recover, start_q/last_q, alpha_mix(1).
neb.x: &PATH
string_method ('neb'/'smd'), num_of_images, nstep_path,
opt_scheme ('broyden'/'quick-min'/'sd'),
CI_scheme ('no-CI'/'auto'/'manual'), path_thr, ds, k_max,
k_min, restart_mode. Input layout in R2.
The file flow on one page
┌─ dos.x ──────→ total DOS
scf ──→ nscf ───────┼─ projwfc.x ──→ PDOS, Löwdin
│ └─ (frozen density)
├────→ bands ──────── bands.x ────→ bands (.gnu)
├────→ pp.x ─────────────────────→ density/potential (cube) ──→ average.x → work function
├────→ hp.x (HUBBARD required) ──→ U, V
└────→ ph.x ──→ q2r.x ──→ matdyn.x → phonon dispersion
Every arrow is glued by the same prefix and outdir. Break the chain
and you get cannot open file ... .save/...
(R3).