A lookup dictionary of pw.x input variables, namelist by namelist.
Defaults are as of QE 7.5, and the final authority is always the
Doc/INPUT_PW.txt of your installed version
(online).
Card syntax is in R2; post-processing variables in
R4.
&CONTROL
| Variable |
Default |
Description |
calculation |
'scf' |
scf / nscf / bands / relax / md / vc-relax / vc-md |
title |
none |
Free text echoed in the output; handy for batch bookkeeping |
verbosity |
'low' |
'high' prints symmetry operations, ns matrices, the k-point list. Always high while learning |
restart_mode |
'from_scratch' |
'restart' resumes an interrupted run |
nstep |
1 for scf, 50 for relax/md |
Number of ionic steps |
dt |
20.0 |
MD time step, in Rydberg atomic units (20 a.u. ≈ 0.968 fs) |
outdir |
./ or $ESPRESSO_TMPDIR |
Location of large temporaries. Point it at a fast disk |
wfcdir |
outdir |
Separate location for wavefunctions if needed |
prefix |
'pwscf' |
Must match across follow-up runs |
pseudo_dir |
$ESPRESSO_PSEUDO or ~/espresso/pseudo |
Where the UPF files live |
disk_io |
depends on calculation |
'none' / 'low' / 'medium' / 'high' / 'nowf'. Use 'none' for MD |
tprnfor |
.false. for scf |
Print forces. Mandatory for ML training data |
tstress |
.false. |
Print stress |
etot_conv_thr |
1.0d-4 Ry |
Energy criterion for ionic optimization |
forc_conv_thr |
1.0d-3 Ry/bohr |
Force criterion for ionic optimization |
max_seconds |
1.0d7 |
Save and exit cleanly before the time limit. Essential in HPC batch jobs |
tefield, dipfield |
.false. |
Sawtooth field / dipole correction switches. They live here in &CONTROL (the position parameters edir etc. are in &SYSTEM) |
lelfield, gate, trism |
.false. |
Special features (finite field / gate / RISM) |
&SYSTEM: lattice and atoms
| Variable |
Description |
ibrav |
0 = explicit CELL_PARAMETERS / 1 simple cubic / 2 fcc / 3 bcc / 4 hexagonal / 5 rhombohedral / 6,7 tetragonal / 8–11 orthorhombic / 12,13 monoclinic / 14 triclinic |
celldm(1..6) |
Lattice parameters per ibrav. celldm(1) is in bohr |
A, B, C, cosAB, cosAC, cosBC |
Alternative to celldm. A is in Å (mind the mix) |
nat, ntyp |
Atom count / type count; must match the cards |
nosym, noinv |
Suppress symmetry / inversion. For special magnetic patterns, MD, or debugging |
ibrav=0 is flexible but symmetry autodetection can degrade; check the
Sym. Ops. count in the output.
&SYSTEM: basis and cutoffs
| Variable |
Default |
Description |
ecutwfc |
required |
Wavefunction cutoff (Ry) |
ecutrho |
4*ecutwfc |
Density cutoff (Ry). US/PAW need 8–12x |
nbnd |
nelec/2 for insulators, more for metals |
Number of bands; be generous for DOS and bands runs |
&SYSTEM: occupations and smearing
| Variable |
Description |
occupations |
'fixed' (insulators) / 'smearing' (metals) / 'tetrahedra' / 'tetrahedra_lin' / 'tetrahedra_opt' (nscf for DOS/bands) / 'from_input' |
smearing |
'gaussian' / 'methfessel-paxton' ('mp') / 'marzari-vanderbilt' ('mv', 'cold') / 'fermi-dirac' ('fd') |
degauss |
Smearing width (Ry); metals typically 0.01–0.02 |
The tetrahedron methods require a Γ-centered, unshifted automatic grid
and belong in nscf runs.
&SYSTEM: spin and magnetism
| Variable |
Description |
nspin |
1 unpolarized / 2 collinear / 4 noncollinear (prefer noncolin) |
starting_magnetization(i) |
Initial polarization ratio (−1 to 1) for type i. Not Bohr magnetons |
tot_magnetization |
Constrains the cell moment; separate up/down Fermi levels |
noncolin |
.true. for noncollinear magnetism |
lspinorb |
Spin-orbit coupling; needs fully relativistic pseudopotentials |
angle1(i), angle2(i) |
Moment directions (degrees) for noncollinear runs |
constrained_magnetization |
'atomic', 'total', ...; strength via lambda |
&SYSTEM: DFT+U (v7.1+ syntax)
U parameters go in the HUBBARD card (R2), not in
&SYSTEM. The related variables that remain here:
| Variable |
Description |
starting_ns_eigenvalue(m, ispin, ityp) |
Forces initial d/f occupation eigenvalues. Essential for systems trapped in wrong minima, like FeO |
Hubbard_occ(ityp, i) |
Overrides the initial occupation of the Hubbard manifold |
Retired syntax: lda_plus_u, lda_plus_u_kind, Hubbard_U(i),
U_projection_type. All replaced by the HUBBARD card in v7.1.
&SYSTEM: functionals, dispersion, isolation, fields
| Variable |
Description |
input_dft |
Overrides the functional baked into the pseudopotential. Avoid |
vdw_corr |
'grimme-d2' / 'grimme-d3' / 'ts-vdw' / 'xdm' / 'mbd' |
assume_isolated |
'none' / 'makov-payne' / 'martyna-tuckerman' ('mt') / 'esm' / '2D' |
edir, emaxpos, eopreg, eamp |
Field direction (1/2/3), position, width, amplitude (the switches tefield/dipfield are in &CONTROL) |
exx_fraction, screening_parameter, nqx1..3 |
Hybrid-functional parameters |
&ELECTRONS
| Variable |
Default |
Description |
electron_maxstep |
100 |
Maximum SCF iterations |
conv_thr |
1.0d-6 |
SCF threshold (Ry). Use 1.0d-12 before hp.x |
mixing_mode |
'plain' |
'plain' (Broyden) / 'TF' / 'local-TF'. Metals, slabs, magnets: 'local-TF' |
mixing_beta |
0.7 |
Mixing fraction. Magnets and metals: 0.1–0.3 |
mixing_ndim |
8 |
Mixing history; more costs memory |
mixing_fixed_ns |
0 |
DFT+U: freeze the ns occupation matrix for the first N iterations. Unsticks stalled SCF in the nosym+U combination (MD); measured in E13 |
diagonalization |
'david' |
'david' / 'cg' / 'ppcg' / 'paro' / 'rmm-davidson'. 'cg' is slow but robust |
diago_david_ndim |
2 |
Davidson workspace; reduce if memory is tight |
startingwfc |
'atomic+random' |
'atomic' / 'random' / 'file' |
startingpot |
'atomic' |
'atomic' / 'file' |
adaptive_thr |
.false. |
Relaxed thresholds in early iterations (hybrids) |
&IONS
| Variable |
Description |
ion_dynamics |
relax: 'bfgs' (default), 'damp' / md: 'verlet', 'langevin' |
ion_temperature |
'not_controlled' / 'rescaling' / 'rescale-v' / 'berendsen' / 'andersen' / 'svr' / 'initial' |
tempw |
Target temperature (K) |
nraise |
Thermostat coupling period |
pot_extrapolation, wfc_extrapolation |
'none' / 'atomic' / 'first_order' / 'second_order'. Large effect on MD speed |
upscale |
Automatic SCF-threshold tightening factor in BFGS |
bfgs_ndim |
1 (default); 2 or more for quasi-Newton |
&CELL
| Variable |
Description |
cell_dynamics |
vc-relax: 'bfgs' / vc-md: 'pr', 'w' |
press |
Target pressure (kbar) |
press_conv_thr |
0.5 kbar (default) |
cell_dofree |
'all' / 'ibrav' / 'x','y','z' / 'xy' etc. / '2Dxy' / '2Dshape' / 'volume' / 'shape'. Slabs: '2Dxy' |
cell_factor |
2.0 (vc-relax); raise it if the cell changes a lot |
wmass |
Cell inertial mass (vc-md) |
Command-line parallel flags
| Flag |
Alias |
Meaning |
Guidance |
-nk |
-npool |
k-point pools |
Most efficient. Divide the k-count; lower it if memory runs out |
-nb |
-nband |
Band groups |
Hybrids and EXX |
-nt |
-ntg |
FFT task groups |
Many bands, many cores |
-nd |
-ndiag |
Diagonalization group |
Square numbers only. Large systems |
-ni |
-nimage |
Image parallelism |
NEB, phonons, hp.x |
-i / -in / -inp |
|
Input file |
|
Environment variables
| Variable |
Purpose |
ESPRESSO_PSEUDO |
Default pseudopotential path when pseudo_dir is absent |
ESPRESSO_TMPDIR |
Default outdir |
OMP_NUM_THREADS |
OpenMP threads. Beware oversubscription with MPI (Chapter 18) |
ESPRESSO_ROOT |
Source-tree path |