Input File Description
Program: pw.x / PWscf / Quantum Espresso

TABLE OF CONTENTS
INTRODUCTION
&CONTROL
calculation  title  verbosity  restart_mode  wf_collect  nstep  iprint  tstress  tprnfor  dt  outdir  wfcdir  prefix  lkpoint_dir  max_seconds  etot_conv_thr  forc_conv_thr  disk_io  pseudo_dir  tefield  dipfield  lelfield  lberry  gdir  nppstr  nberrycyc
&SYSTEM
ibrav  celldm  A  B  C  cosAB  cosAC  cosBC  nat  ntyp  nbnd  nelec  tot_charge  ecutwfc  ecutrho  nr1  nr2  nr3  nr1s  nr2s  nr3s  nosym  noinv  occupations  degauss  smearing  nspin  noncolin  starting_magnetization  nelup  neldw  multiplicity  tot_magnetization  ecfixed  qcutz  q2sigma  xc_type  lda_plus_u  Hubbard_alpha  Hubbard_U  starting_ns_eigenvalue(m,ispin,I)  U_projection_type  edir  emaxpos  eopreg  eamp  angle1  angle2  constrained_magnetization  fixed_magnetization  B_field  lambda  report  lspinorb  assume_isolated
&ELECTRONS
electron_maxstep  conv_thr  mixing_mode  mixing_beta  mixing_ndim  mixing_fixed_ns  diagonalization  ortho_para  diago_thr_init  diago_cg_maxiter  diago_david_ndim  diago_full_acc  efield  startingpot  startingwfc  tqr
&IONS
ion_dynamics  phase_space  pot_extrapolation  wfc_extrapolation  remove_rigid_rot  ion_temperature  tempw  tolp  delta_t  nraise  refold_pos  upscale  bfgs_ndim  trust_radius_max  trust_radius_min  trust_radius_ini  w_1  w_2  num_of_images  opt_scheme  CI_scheme  first_last_opt  temp_req  ds  k_max  k_min  path_thr  use_masses  use_freezing  fe_step  g_amplitude  fe_nstep  sw_nstep
&CELL
cell_dynamics  press  wmass  cell_factor  press_conv_thr  cell_dofree
&PHONON
modenum  xqq
ATOMIC_SPECIES
X  Mass_X  PseudoPot_X
ATOMIC_POSITIONS
X  x  y  z  if_pos(1)  if_pos(2)  if_pos(3) 
K_POINTS
nks  xk_x  xk_y  xk_z  wk  nk1  nk2  nk3  sk1  sk2  sk3
CELL_PARAMETERS
v1  v2  v3
CLIMBING_IMAGES index1, index2, ... indexN
CONSTRAINTS
nconstr  constr_tol  constr_type  constr(1)  constr(2)  constr(3)  constr(4)  constr_target
COLLECTIVE_VARS
ncolvar  colvar_tol  colvar_type  colvar(1)  colvar(2)  colvar(3)  colvar(4)
OCCUPATIONS
f_inp1  f_inp2
INTRODUCTIONInput data format: { } = optional, [ ] = it depends,  = or
All quantities whose dimensions are not explicitly specified are in RYDBERG ATOMIC UNITS
Structure of the input data: ===============================================================================
&CONTROL ... /
&SYSTEM ... /
&ELECTRONS ... /
[ &IONS ... / ]
[ &CELL ... / ]
[ &PHONON ... / ]
ATOMIC_SPECIES X Mass_X PseudoPot_X Y Mass_Y PseudoPot_Y Z Mass_Z PseudoPot_Z
ATOMIC_POSITIONS { alat  bohr  crystal  angstrom } in all cases except calculation = 'neb' or 'smd' : X 0.0 0.0 0.0 {if_pos(1) if_pos(2) if_pos(3)} Y 0.5 0.0 0.0 Z O.0 0.2 0.2 if calculation = 'neb' .OR. 'smd' : first_image X 0.0 0.0 0.0 {if_pos(1) if_pos(2) if_pos(3)} Y 0.5 0.0 0.0 Z O.0 0.2 0.2 { intermediate_image 1 X 0.0 0.0 0.0 Y 0.9 0.0 0.0 Z O.0 0.2 0.2 intermediate_image ... X 0.0 0.0 0.0 Y 0.9 0.0 0.0 Z O.0 0.2 0.2 } last_image X 0.0 0.0 0.0 Y 0.7 0.0 0.0 Z O.0 0.5 0.2
K_POINTS { tpiba  automatic  crystal  gamma } if (gamma) nothing to read if (automatic) nk1, nk2, nk3, k1, k2, k3 if (not automatic) nks xk_x, xk_y, xk_z, wk
[ CELL_PARAMETERS { cubic  hexagonal } v1(1) v1(2) v1(3) v2(1) v2(2) v2(3) v3(1) v3(2) v3(3) ]
[ OCCUPATIONS f_inp1(1) f_inp1(2) f_inp1(3) ... f_inp1(10) f_inp1(11) f_inp1(12) ... f_inp1(nbnd) [ f_inp2(1) f_inp2(2) f_inp2(3) ... f_inp2(10) f_inp2(11) f_inp2(12) ... f_inp2(nbnd) ] ]
[ CLIMBING_IMAGES list of images, separated by a comma ]
[ CONSTRAINTS nconstr { constr_tol } constr_type(.) constr(1,.) constr(2,.) [ constr(3,.) constr(4,.) ] { constr_target(.) } ]
[ COLLECTIVE_VARS ncolvar { colvar_tol } colvar_type(.) colvar(1,.) colvar(2,.) [ colvar(3,.) colvar(4,.) ] ]
Namelist: CONTROL 
calculation 
CHARACTER 
Default: 
'scf'

a string describing the task to be performed: 'scf', 'nscf', 'bands', 'phonon', 'relax', 'md', 'vcrelax', 'vcmd', 'neb', 'smd', 'metadyn' (vc = variablecell).

title 
CHARACTER 
Default: 
' '

reprinted on output.

verbosity 
CHARACTER 
'high'  'default'  'low'  'minimal'

restart_mode 
CHARACTER 
Default: 
'from_scratch'

'from_scratch' : from scratch NEB and SMD only: the starting path is obtained with a linear interpolation between the images specified in the ATOMIC_POSITIONS card. Note that in the linear interpolation periodic boundary conditions ARE NON USED.
'restart' : from previous interrupted run

wf_collect 
LOGICAL 
Default: 
.FALSE.

This flag controls the way wavefunctions are stored to disk :
.TRUE. collect wavefunctions from all processors and store them into the output data directory outdir/prefix.save
.FALSE. do not collect wavefunctions, leave them in temporary local files (one per processor). The resulting format will be readable only by jobs running on the same number of processors and pools. Useful if you do not need the wavefunction or if you want to reduce the I/O or the disk occupancy.

nstep 
INTEGER 
Default: 
1 if calculation = 'scf', 'nscf', 'bands';
0 if calculation = 'neb', 'smd';
50 for the other cases

number of ionic + electronic steps

iprint 
INTEGER 
Default: 
write only at convergence

band energies are written every iprint iterations

tstress 
LOGICAL 
calculate stress. Set to .TRUE. if calculation='vcmd'

tprnfor 
LOGICAL 
print forces. Set to .TRUE. if calculation='relax','md','vcmd'

dt 
REAL 
Default: 
20.D0

time step for molecular dynamics, in Rydberg atomic units (1 a.u.=4.8378 * 10^17 s : beware, CP and FPMD codes use Hartree atomic units, half that much!!!)

outdir 
CHARACTER 
Default: 
value of the ESPRESSO_TMPDIR environment variable if set;
current directory ('./') otherwise

input, temporary, output files are found in this directory, see also 'wfcdir'

wfcdir 
CHARACTER 
Default: 
same as outdir

this directory specifies where to store files generated by each processor (*.wfc{N}, *.igk{N}, etc.). The idea here is to be able to separately store the largest files, while the files necessary for restarting still go into 'outdir' (for now only works for stand alone PW )

prefix 
CHARACTER 
Default: 
'pwscf'

prepended to input/output filenames: prefix.wfc, prefix.rho, etc.

lkpoint_dir 
LOGICAL 
Default: 
.true.

If .false. it does not open a subdirectory for each k_point in the prefix.save directory.

max_seconds 
REAL 
Default: 
1.D+7, or 150 days, i.e. no time limit

jobs stops after max_seconds CPU time

etot_conv_thr 
REAL 
Default: 
1.0D4

convergence threshold on total energy (a.u) for ionic minimization: the convergence criterion is satisfied when the total energy changes less than etot_conv_thr between two consecutive scf steps. See also forc_conv_thr  both criteria must be satisfied

forc_conv_thr 
REAL 
Default: 
1.0D3

convergence threshold on forces (a.u) for ionic minimization: the convergence criterion is satisfied when all components of all forces are smaller than forc_conv_thr. See also etot_conv_thr  both criteria must be satisfied

disk_io 
CHARACTER 
Default: 
'default'

Specifies the amount of disk I/O activity 'high': save all data at each SCF step
'default': save wavefunctions at each SCF step unless there is a single kpoint per process
'low' : store wfc in memory, save only at the end
'none': do not save wfc, not even at the end
If restarting from an interrupted calculation, the code will try to figure out what is available on disk. The more you write, the more complete the restart will be.

pseudo_dir 
CHARACTER 
Default: 
value of the $ESPRESSO_PSEUDO environment variable if set;
'$HOME/espresso/pseudo/' otherwise

directory containing pseudopotential files

tefield 
LOGICAL 
Default: 
.FALSE.

If .TRUE. a sawlike potential simulating an electric field is added to the bare ionic potential. See variables edir, eamp, emaxpos, eopreg for the form and size of the added potential.

dipfield 
LOGICAL 
Default: 
.FALSE.

If .TRUE. and tefield=.TRUE. a dipole correction is also added to the bare ionic potential  implements the recipe of L. Bengtsson, PRB 59, 12301 (1999). See variables edir, emaxpos, eopreg for the form of the correction, that must be used only in a slab geometry, for surface calculations, with the discontinuity in the empty space.

lelfield 
LOGICAL 
Default: 
.FALSE.

If .TRUE. a homogeneous finite electric field described through the modern theory of the polarization is applied. This is different from "tefield=.true." !

lberry 
LOGICAL 
Default: 
.FALSE.

If .TRUE. perform a Berry phase calculation See the header of PW/bp_c_phase.f90 for documentation

gdir 
INTEGER 
For Berry phase calculation: direction of the kpoint strings in reciprocal space. Allowed values: 1, 2, 3 1=first, 2=second, 3=third reciprocal lattice vector For calculations with finite electric fields (lelfield==.true.), gdir is the direction of the field

nppstr 
INTEGER 
For Berry phase calculation: number of kpoints to be calculated along each symmetryreduced string The same for calculation with finite electric fields (lelfield==.true.)

nberrycyc 
INTEGER 
Default: 
1

In the case of a finite electric field ( lelfield == .TRUE. ) it defines the number of iterations for converging the wavefunctions in the electric field Hamiltonian, for each external iteration on the charge density



Namelist: SYSTEM 
ibrav 
INTEGER 
Status: 
REQUIRED

Bravaislattice index:
ibrav structure celldm(2)celldm(6)
0 "free", see above not used 1 cubic P (sc) not used 2 cubic F (fcc) not used 3 cubic I (bcc) not used 4 Hexagonal and Trigonal P celldm(3)=c/a 5 Trigonal R celldm(4)=cos(alpha) 6 Tetragonal P (st) celldm(3)=c/a 7 Tetragonal I (bct) celldm(3)=c/a 8 Orthorhombic P celldm(2)=b/a,celldm(3)=c/a 9 Orthorhombic basecentered(bco) celldm(2)=b/a,celldm(3)=c/a 10 Orthorhombic facecentered celldm(2)=b/a,celldm(3)=c/a 11 Orthorhombic bodycentered celldm(2)=b/a,celldm(3)=c/a 12 Monoclinic P celldm(2)=b/a,celldm(3)=c/a, celldm(4)=cos(ab) 13 Monoclinic basecentered celldm(2)=b/a,celldm(3)=c/a, celldm(4)=cos(ab) 14 Triclinic celldm(2)= b/a, celldm(3)= c/a, celldm(4)= cos(bc), celldm(5)= cos(ac), celldm(6)= cos(ab)
For P lattices: the special axis (c) is the zaxis, one basalplane vector (a) is along x, the other basalplane vector (b) is at angle gamma for monoclinic, at 120 degrees for trigonal and hexagonal lattices, at 90 degrees for cubic, tetragonal, orthorhombic lattices
sc simple cubic ==================== v1 = a(1,0,0), v2 = a(0,1,0), v3 = a(0,0,1)
fcc face centered cubic ==================== v1 = (a/2)(1,0,1), v2 = (a/2)(0,1,1), v3 = (a/2)(1,1,0).
bcc body entered cubic ==================== v1 = (a/2)(1,1,1), v2 = (a/2)(1,1,1), v3 = (a/2)(1,1,1).
simple hexagonal and trigonal(p) ==================== v1 = a(1,0,0), v2 = a(1/2,sqrt(3)/2,0), v3 = a(0,0,c/a).
trigonal(r) =================== for these groups, the zaxis is chosen as the 3fold axis, but the crystallographic vectors form a threefold star around the zaxis, and the primitive cell is a simple rhombohedron. The crystallographic vectors are: v1 = a(tx,ty,tz), v2 = a(0,2ty,tz), v3 = a(tx,ty,tz). where c=cos(alpha) is the cosine of the angle alpha between any pair of crystallographic vectors, tc, ty, tz are defined as tx=sqrt((1c)/2), ty=sqrt((1c)/6), tz=sqrt((1+2c)/3)
simple tetragonal (p) ==================== v1 = a(1,0,0), v2 = a(0,1,0), v3 = a(0,0,c/a)
body centered tetragonal (i) ================================ v1 = (a/2)(1,1,c/a), v2 = (a/2)(1,1,c/a), v3 = (a/2)(1,1,c/a).
simple orthorhombic (p) ============================= v1 = (a,0,0), v2 = (0,b,0), v3 = (0,0,c)
bco base centered orthorhombic ============================= v1 = (a/2,b/2,0), v2 = (a/2,b/2,0), v3 = (0,0,c)
face centered orthorhombic ============================= v1 = (a/2,0,c/2), v2 = (a/2,b/2,0), v3 = (0,b/2,c/2)
body centered orthorhombic ============================= v1 = (a/2,b/2,c/2), v2 = (a/2,b/2,c/2), v3 = (a/2,b/2,c/2)
monoclinic (p) ============================= v1 = (a,0,0), v2= (b*cos(gamma), b*sin(gamma), 0), v3 = (0, 0, c) where gamma is the angle between axis a and b
base centered monoclinic ============================= v1 = ( a/2, 0, c/2), v2 = (b*cos(gamma), b*sin(gamma), 0), v3 = ( a/2, 0, c/2), where gamma is the angle between axis a and b
triclinic ============================= v1 = (a, 0, 0), v2 = (b*cos(gamma), b*sin(gamma), 0) v3 = (c*cos(beta), c*(cos(alpha)cos(beta)cos(gamma))/sin(gamma), c*sqrt( 1 + 2*cos(alpha)cos(beta)cos(gamma)  cos(alpha)^2cos(beta)^2cos(gamma)^2 )/sin(gamma) ) where alpha is the angle between axis b and c beta is the angle between axis a and c gamma is the angle between axis a and b

celldm(i), i=1,6 
REAL 
See: 
ibrav

Crystallographic constants  see description of ibrav variable.
* alat = celldm(1) is the lattice parameter "a" (in BOHR) * only needed celldm (depending on ibrav) must be specified * if ibrav=0 only alat = celldm(1) is used (if present)

A, B, C, cosAB, cosAC, cosBC

REAL 
Traditional crystallographic constants (a,b,c in ANGSTROM), cosab = cosine of the angle between axis a and b specify either these OR celldm but NOT both. If ibrav=0 only alat = a is used (if present)

nat 
INTEGER 
Status: 
REQUIRED

number of atoms in the unit cell

ntyp 
INTEGER 
Status: 
REQUIRED

number of types of atoms in the unit cell

nbnd 
INTEGER 
Default: 
for an insulator, nbnd = number of valence bands
(nbnd=nelec/2, see below for nelec);
for a metal, 20% more (minimum 4 more)

number of electronic states (bands) to be calculated. Note that in spinpolarized calculations the number of kpoint, not the number of bands per kpoint, is doubled

nelec 
REAL 
Default: 
the same as ionic charge (neutral cell)

number of electron in the unit cell (may be noninteger if you wish)
A compensating jellium background is inserted to remove divergences if the cell is not neutral

tot_charge 
INTEGER 
Default: 
0

total system charge. Used only if nelec is unspecified, otherwise it is ignored.

ecutwfc 
REAL 
Status: 
REQUIRED

kinetic energy cutoff (Ry) for wavefunctions

ecutrho 
REAL 
Default: 
4 * ecutwfc

kinetic energy cutoff (Ry) for charge density and potential May be larger ( for ultrasoft PP ) or somewhat smaller ( but not much smaller ) than the default value. Note that if you have normconserving PP only, setting it to a larger value than the default is a waste of time.

nr1, nr2, nr3

INTEGER 
threedimensional FFT mesh (hard grid) for charge density (and scf potential). If not specified the grid is calculated based on the cutoff for charge density (see also "ecutrho")

nr1s, nr2s, nr3s

INTEGER 
threedimensional mesh for wavefunction FFT and for the smooth part of charge density ( smooth grid ). Coincides with nr1, nr2, nr3 if ecutrho = 4 * ecutwfc ( default )

nosym 
LOGICAL 
Default: 
.FALSE.

if (.TRUE.) symmetry is not used. Note that a kpoint grid provided in input is used "as is"; an automatically generated kpoint grid will contain only points in the irreducible BZ of the lattice. Use with care in lowsymmetry large cells if you cannot afford a kpoint grid with the correct symmetry.

noinv 
LOGICAL 
Default: 
.FALSE.

if (.TRUE.) disable the usage of time reversal (q => q) symmetry in kpoint generation

occupations 
CHARACTER 
'smearing': gaussian smearing for metals requires a value for degauss
'tetrahedra' : for metals and DOS calculation (see PRB49, 16223 (1994)) Requires uniform grid of kpoints, automatically generated (see below) Not suitable (because not variational) for force/optimization/dynamics calculations
'fixed' : for insulators with a gap
'from_input' : The occupation are read from input file. Presently works only with one kpoint (LSDA allowed).

degauss 
REAL 
Default: 
0.D0 Ry

value of the gaussian spreading (Ry) for brillouinzone integration in metals.

smearing 
CHARACTER 
Default: 
'gaussian'

'gaussian', 'gauss': ordinary Gaussian spreading (Default)
'methfesselpaxton', 'mp', 'mp': MethfesselPaxton firstorder spreading (see PRB 40, 3616 (1989)).
'marzarivanderbilt', 'cold', 'mv', 'mv': MarzariVanderbilt cold smearing (see PRL 82, 3296 (1999))
'fermidirac', 'fd', 'fd': smearing with FermiDirac function

nspin 
INTEGER 
Default: 
1

nspin = 1 : nonpolarized calculation (default)
nspin = 2 : spinpolarized calculation, LSDA (magnetization along z axis)
nspin = 4 : spinpolarized calculation, noncollinear (magnetization in generic direction) DO NOT specify nspin in this case; specify "noncolin=.TRUE." instead

noncolin 
LOGICAL 
Default: 
.false.

if .true. the program will perform a noncollinear calculation.

starting_magnetization(i), i=1,ntyp 
REAL 
starting spin polarization (values between 1 and 1) on atomic type 'i' in a spinpolarized calculation. Breaks the symmetry and provides a starting point for selfconsistency. The default value is zero, BUT a value MUST be specified for AT LEAST one atomic type in spin polarized calculations. Note that if start from zero initial magnetization, you will get zero final magnetization in any case. If you desire to start from an antiferromagnetic state, you may need to define two different atomic species corresponding to sublattices of the same atomic type. If you fix the magnetization with "nelup/neldw" or with "multiplicity" or with "tot_magnetization", you should not specify starting_magnetization. If you are restarting from a previous run, or from an interrupted run, starting_magnetization is ignored.

nelup, neldw

REAL 
number of spinup and spindown electrons, respectively Note that this fixes the final value of the magnetization. The sum must yield nelec that must also be specified explicitly in this case. Not valid for spinunpolarized or noncollinear calculations, only for LSDA. Obsolescent: use multiplicity or tot_magnetization instead.

multiplicity 
INTEGER 
Default: 
0 [unspecified]

spin multiplicity (2s+1). 1 is singlet, 2 for doublet etc. Note that this fixes the final value of the magnetization. if unspecified or a nonzero value is specified in nelup/neldw then multiplicity variable is ignored. Do not specify both multiplicity and tot_magnetization.

tot_magnetization 
INTEGER 
Default: 
1 [unspecified]

majority spin  minority spin (nelup  neldw). if unspecified or a nonzero value is specified in nelup/neldw then tot_magnetization variable is ignored. Do not specify both multiplicity and tot_magnetization. YES, there is redundancy! nelup/neldw are enough to specify the spin state. However these variables are not very convenient and will be eliminated from the input in future versions. It is recommended to use either 'multiplicity' or equivalently 'tot_magnetization' to specify the spin state.

ecfixed 
REAL 
Default: 
0.0

See: 
q2sigma

qcutz 
REAL 
Default: 
0.0

See: 
q2sigma

q2sigma 
REAL 
Default: 
0.1

ecfixed, qcutz, q2sigma: parameters for modified functional to be used in variablecell molecular dynamics (or in stress calculation). "ecfixed" is the value (in Rydberg) of the constantcutoff; "qcutz" and "q2sigma" are the height and the width (in Rydberg) of the energy step for reciprocal vectors whose square modulus is greater than "ecfixed". In the kinetic energy, G^2 is replaced by G^2 + qcutz * (1 + erf ( (G^2  ecfixed)/q2sigma) ) See: M. Bernasconi et al, J. Phys. Chem. Solids 56, 501 (1995)

xc_type 
CHARACTER 
Status: 
presently UNUSED: XC functional is read from PP files

Exchangecorrelation functional

lda_plus_u 
LOGICAL 
Default: 
.FALSE.

See: 
Hubbard_U

Hubbard_alpha(i), i=1,ntyp 
REAL 
Default: 
0.D0 for all species

See: 
Hubbard_U

Hubbard_U(i), i=1,ntyp 
REAL 
Default: 
0.D0 for all species

Status: 
LDA+U works only for a few selected elements. Modify
PW/set_hubbard_l.f90 and PW/tabd.f90 if you plan to use LDA+U with an
element that is not configured there.

lda_plus_u, Hubbard_alpha(i), Hubbard_U(i): parameters for LDA+U calculations If lda_plus_u = .TRUE. you must specify, for species i, the parameters U and (optionally) alpha of the Hubbard model (both in eV). See: Anisimov, Zaanen, and Andersen, PRB 44, 943 (1991); Anisimov et al., PRB 48, 16929 (1993); Liechtenstein, Anisimov, and Zaanen, PRB 52, R5467 (1994); Cococcioni and de Gironcoli, PRB 71, 035105 (2005).

starting_ns_eigenvalue(m,ispin,I) 
REAL 
Default: 
1.d0 that means NOT SET

In the first iteration of an LDA+U run it overwrites the mth eigenvalue of the ns occupation matrix for the ispin component of atomic species I. Leave unchanged eigenvalues that are not set. This is useful to suggest the desired orbital occupations when the default choice takes another path.

U_projection_type 
CHARACTER 
Default: 
'atomic'

Only active when lda_plus_U is .true., specifies the type of projector on localized orbital to be used in the LDA+U scheme.
Currently available choices: 'atomic': use atomic wfc's (as they are) to build the projector
'orthoatomic': use Lowdin orthogonalized atomic wfc's
'normatomic': Lowdin normalization of atomic wfc. Keep in mind: atomic wfc are not orthogonalized in this case. This is a "quick and dirty" trick to be used when atomic wfc from the pseudopotential are not normalized (and thus produce occupation whose value exceeds unity). If orthogonalized wfc are not needed always try 'atomic' first.
'file': use the information from file "prefix".atwfc that must have been generated previously, for instance by pmw.x (see PP/poormanwannier.f90 for details)
NB: forces and stress currently implemented only for the 'atomic' choice.

edir 
INTEGER 
The direction of the electric field or dipole correction is parallel to the bg(:,edir) reciprocal lattice vector, so the potential is constant in planes defined by FFT grid points; edir = 1, 2 or 3. Used only if tefield is .TRUE.

emaxpos 
REAL 
Default: 
0.5D0

Position of the maximum of the sawlike potential along crystal axis "edir", within the unit cell (see below), 0 < emaxpos < 1 Used only if tefield is .TRUE.

eopreg 
REAL 
Default: 
0.1D0

Zone in the unit cell where the sawlike potential decreases. ( see below, 0 < eopreg < 1 ). Used only if tefield is .TRUE.

eamp 
REAL 
Default: 
0.001 a.u.

Amplitude of the electric field (in a.u. = 51.44 10^10 V/m ) The sawlike potential increases with slope "eamp" in the region from (emaxpos+eopreg1) to (emaxpos), then decreases to 0 until (emaxpos+eopreg), in units of the crystal vector "edir". Used only if tefield is .TRUE.

angle1(i), i=1,ntyp 
REAL 
The angle expressed in degrees between the initial magnetization and the zaxis. For noncollinear calculations only; index i runs over the atom types.

angle2(i), i=1,ntyp 
REAL 
The angle expressed in degrees between the projection of the initial magnetization on xy plane and the xaxis. For noncollinear calculations only.

constrained_magnetization 
CHARACTER 
Default: 
'none'

Used to perform constrained calculations in magnetic systems. Currently available choices:
'none': no constraint
'total': total magnetization is constrained If nspin=4 (noncolin=.True.) constraint is imposed by adding a penalty functional to the total energy:
LAMBDA * SUM_{i} ( magnetization(i)  fixed_magnetization(i) )**2
where the sum over i runs over the three components of the magnetization. Lambda is a real number (see below). If nspin=2 constraint is imposed by defining two Fermi energies for spin up and down. Only fixed_magnetization(3) can be defined in this case.
'atomic': atomic magnetization are constrained to the defined starting magnetization adding a penalty:
LAMBDA * SUM_{i,itype} ( magnetic_moment(i,itype)  mcons(i,itype) )**2
where i runs over the cartesian components (or just z in the collinear case) and itype over the types (1ntype). mcons(:,:) array is defined from starting_magnetization, (and angle1, angle2 in the noncollinear case). lambda is a real number
'total direction': the angle theta of the total magnetization with the z axis (theta = fixed_magnetization(3)) is constrained:
LAMBDA * ( magnetization(1)  magnetization(3)*tan(theta) )**2
'atomic direction': not all the components of the atomic magnetic moment are constrained but only the cosine of angle1, and the penalty functional is:
LAMBDA * SUM_{itype} ( mag_mom(3,itype)/mag_mom_tot  cos(angle1(ityp)) )**2

fixed_magnetization(i), i=1,3 
REAL 
Default: 
0.d0

value of the total magnetization to be maintained fixed when constrained_magnetization='total'

B_field(i), i=1,3 
REAL 
Default: 
0.d0

A fixed magnetic field defined by the vector B_field is added to the exchange and correlation magnetic field. The three components of the magnetic field are given in Ry. Only B_field(3) can be used if nspin=2.
In all calculations with a finite magnetic field, we print the total energy WITHOUT the B dot M term. In the calculations with the penalty functional we write only the total energy, NOT the penalty functional.

lambda 
REAL 
parameter used for constrained_magnetization calculations NB: LAMBDA is reduced in the first iterations and is increased slowly up to the input value.

report 
INTEGER 
It's the number of iterations after which the program write all the atomic magnetic moments.

lspinorb 
LOGICAL 
if .TRUE. the noncollinear code can use a pseudopotential with spinorbit.

assume_isolated 
LOGICAL 
Default: 
.FALSE.

if .TRUE. the system is assumed to be isolated (a molecule or cluster in a supercell) and the MakovPayne correction to the total energy is computed. An estimate of the vacuum level is also calculated so that eigenvalues can be properly aligned.



Namelist: ELECTRONS 
electron_maxstep 
INTEGER 
Default: 
100

maximum number of iterations in a scf step

conv_thr 
REAL 
Default: 
1.D6

Convergence threshold for selfconsistency: estimated energy error < conv_thr

mixing_mode 
CHARACTER 
Default: 
'plain'

'plain' : charge density Broyden mixing
'TF' : as above, with simple ThomasFermi screening (for highly homogeneous systems)
'localTF': as above, with localdensitydependent TF screening (for highly inhomogeneous systems)

mixing_beta 
REAL 
Default: 
0.7D0

mixing factor for selfconsistency

mixing_ndim 
INTEGER 
Default: 
8

number of iterations used in mixing scheme

mixing_fixed_ns 
INTEGER 
Default: 
0

For LDA+U : number of iterations with fixed ns ( ns is the atomic density appearing in the Hubbard term ).

diagonalization 
CHARACTER 
Default: 
'david'

'david': Davidson iterative diagonalization with overlap matrix (default). Fast, may in some rare cases fail.
'cg' : conjugategradientlike bandbyband diagonalization Typically slower than 'david' but it uses less memory and is more robust (it fails very seldom)
'davidserial': do not use parallel subspace diagonalization in Davidson algorithm (for testing purposes). The subspace diagonalization in Davidson is performed by a fully distributedmemory parallel algorithm on 4 or more processors, by default. The allocated memory scales down with the number of procs. Procs involved in diagonalization can be changed with input parameter "ortho_para". On multicore CPUs often it is convenient to let only one core per CPU to work on linear algebra.

ortho_para 
INTEGER 
Default: 
0

Status: 
OBSOLESCENT: use commandline option " ndiag XX" instead

meaningful for diagonalization='david' and parallel executables. The number of processors to be used for the parallel subspace diagonalization algorithm. With the default value (0) the code tries to use as many processors as available. Note that the algorithm uses a square number of processors (4, 9, 16, 25,...), so the actual number of processors used will be the largest square number less or equal to ortho_para (if set) or to the total number of processors (if ortho_para is not set).

diago_thr_init 
REAL 
Convergence threshold for the first iterative diagonalization (the check is on eigenvalue convergence). For scf calculations, the default is 1.D2 if starting from a superposition of atomic orbitals; 1.D5 if starting from a charge density. During self consistency the threshold (ethr) is automatically reduced when approaching convergence. For nonscf calculations, this is the threshold used in the iterative diagonalization. The default is conv_thr / nelec. For 'phonon' calculations, diago_thr_init is ignored: the threshold is always set to conv_thr / nelec .

diago_cg_maxiter 
INTEGER 
For conjugate gradient diagonalization: max number of iterations

diago_david_ndim 
INTEGER 
Default: 
4

For Davidson diagonalization: dimension of workspace (number of wavefunction packets, at least 2 needed). A larger value may yield a faster algorithm but uses more memory

diago_full_acc 
LOGICAL 
Default: 
.FALSE.

If .TRUE. all the empty states are diagonalized at the same level of accuracy of the occupied ones. Otherwise the empty states are diagonalized using a larger threshold (this should not affect total energy, forces, and other groundstate properties).

efield 
REAL 
Default: 
0.D0

For finite electric field calculations (lelfield == .TRUE.), it defines the intensity of the field in a.u.

startingpot 
CHARACTER 
'atomic': starting potential from atomic charge superposition ( default for scf, *relax, *md, neb, smd )
'file' : start from existing "chargedensity.xml" file ( default, only possibility for nscf, bands, phonon )

startingwfc 
CHARACTER 
Default: 
'atomic'

'atomic': start from superposition of atomic orbitals If not enough atomic orbitals are available, fill with random numbers the remaining wfcs The scf typically starts better with this option, but in some highsymmetry cases one can "loose" valence states, ending up in the wrong ground state.
'atomic+random': as above, plus a superimposed "randomization" of atomic orbitals. Prevents the "loss" of states mentioned above.
'random': start from random wfcs. Slower start of scf but safe. It may also reduce memory usage in conjunction with diagonalization='cg'
'file': start from a wavefunction file

tqr 
LOGICAL 
Default: 
.FALSE.

If .true., use the (VERY EXPERIMENTAL) realspace algorithm for augmentation charges in ultrasoft pseudopotentials. Must faster execution of ultrasoftrelated calculations, but numerically less accurate than the default algorithm. Use with care and after testing!



Namelist: IONS 
input this namelist only if calculation = 'relax', 'md', 'vcrelax', 'vcmd', 'neb', 'smd'
ion_dynamics 
CHARACTER 
Specify the type of ionic dynamics.
For constrained dynamics or constrained optimisations add the CONSTRAINTS card (when the card is present the SHAKE algorithm is automatically used).
For different type of calculation different possibilities are allowed and different default values apply:
CASE ( calculation = 'relax' ) 'bfgs' : (default) a new BFGS quasinewton algorithm, based on the trust radius procedure, is used for structural relaxation (experimental) 'damp' : use damped (quickmin Verlet) dynamics for structural relaxation
CASE ( calculation = 'md' ) 'verlet' : (default) use Verlet algorithm to integrate Newton's equation 'langevin' ion dynamics is overdamped Langevin
CASE ( calculation = 'vcrelax' ) 'damp' : (default) use damped (Beeman) dynamics for structural relaxation
CASE ( calculation = 'vcmd' ) 'beeman' : (default) use Beeman algorithm to integrate Newton's equation

phase_space 
CHARACTER 
Default: 
'full'

'full' : the full phasespace is used for the ionic dynamics.
'coarsegrained' : a coarsegrained phasespace, defined by a set of constraints, is used for the ionic dynamics (used for calculation of freeenergy barriers)

pot_extrapolation 
CHARACTER 
Default: 
'atomic'

Used to extrapolate the potential from preceding ionic steps.
'none' : no extrapolation
'atomic' : extrapolate the potential as if it was a sum of atomiclike orbitals
'first_order' : extrapolate the potential with firstorder formula
'second_order': as above, with second order formula

wfc_extrapolation 
CHARACTER 
Default: 
'none'

Used to extrapolate the wavefunctions from preceding ionic steps.
'none' : no extrapolation
'first_order' : extrapolate the wavefunctions with firstorder formula  NOT IMPLEMENTED WITH USPP
'second_order': as above, with second order formula NOT IMPLEMENTED WITH USPP

remove_rigid_rot 
LOGICAL 
Default: 
.FALSE.

This keyword is useful when simulating the dynamics and/or the thermodynamics of an isolated system. If set to true the total torque of the internal forces is set to zero by adding new forces that compensate the spurious interaction with the periodic images. This allowes for the use of smaller supercells.
BEWARE: since the potential energy is no longer consistent with the forces (it still contains the spurious interaction with the repeated images), the total energy is not conserved anymore. However the dynamical and thermodynamical properties should be in closer agreement with those of an isolated system. Also the final energy of a structural relaxation will be higher, but the relaxation itself should be faster.

keywords used for molecular dynamics
ion_temperature 
CHARACTER 
Default: 
'not_controlled'

'rescaling' control ionic temperature via velocity rescaling (first method) see parameters "tempw" and "tolp" This is the only method implemented in VCMD
'rescalev' control ionic temperature via velocity rescaling (second method) see parameters "tempw" and "nraise"
'rescaleT' control ionic temperature via velocity rescaling (third method) see parameter "delta_t"
'reduceT' reduce ionic temperature every "nraise" steps by the (negative) value "delta_t"
'berendsen' control ionic temperature using "soft" velocity rescaling  see parameters "tempw" and "nraise"
'andersen' control ionic temperature using Andersen thermostat see parameters "tempw" and "nraise"
'not_controlled' (default) ionic temperature is not controlled

tempw 
REAL 
Default: 
300.D0

Starting temperature (Kelvin) in MD runs target temperature for most thermostats.

tolp 
REAL 
Default: 
100.D0

Tolerance for velocity rescaling. Velocities are rescaled if the runaveraged and target temperature differ more than tolp.

delta_t 
REAL 
Default: 
1.D0

if ion_temperature='rescaleT': at each step the instantaneous temperature is multiplied by delta_t; this is done rescaling all the velocities.
if ion_temperature='reduceT': every 'nraise' steps the instantaneous temperature is reduced by delta_T (.e. delta_t is added to the temperature)
The instantaneous temperature is calculated at the end of every ionic move and BEFORE rescaling. This is the temperature reported in the main output.
For delta_t < 0, the actual average rate of heating or cooling should be roughly C*delta_t/(nraise*dt) (C=1 for an ideal gas, C=0.5 for a harmonic solid, theorem of energy equipartition between all quadratic degrees of freedom).

nraise 
INTEGER 
Default: 
1

if ion_temperature='reduceT': every 'nraise' steps the instantaneous temperature is reduced by delta_T (.e. delta_t is added to the temperature)
if ion_temperature='rescalev': every 'nraise' steps the average temperature, computed from the last nraise steps, is rescaled to tempw
if ion_temperature='berendsen': the "rise time" parameter is given in units of the time step: tau = nraise*dt, so dt/tau = 1/nraise
if ion_temperature='andersen': the "collision frequency" parameter is given as nu=1/tau defined above, so nu*dt = 1/nraise

refold_pos 
LOGICAL 
Default: 
.FALSE.

This keyword applies only in the case of molecular dynamics or damped dynamics. If true the ions are refolded at each step into the supercell.


keywords used only in BFGS calculations
upscale 
REAL 
Default: 
10.D0

Max reduction factor for conv_thr during structural optimization conv_thr is automatically reduced when the relaxation approaches convergence so that forces are still accurate, but conv_thr will not be reduced to less that conv_thr / upscale.

bfgs_ndim 
INTEGER 
Default: 
1

Number of old forces and displacements vectors used in the PULAY mixing of the residual vectors obtained on the basis of the inverse hessian matrix given by the BFGS algorithm. When bfgs_ndim = 1, the standard quasiNewton BFGS method is used. (bfgs only)

trust_radius_max 
REAL 
Default: 
0.8D0

Maximum ionic displacement in the structural relaxation. (bfgs only)

trust_radius_min 
REAL 
Default: 
1.D3

Minimum ionic displacement in the structural relaxation BFGS is reset when trust_radius < trust_radius_min. (bfgs only)

trust_radius_ini 
REAL 
Default: 
0.5D0

Initial ionic displacement in the structural relaxation. (bfgs only)

w_1 
REAL 
Default: 
0.01D0

See: 
w_2

w_2 
REAL 
Default: 
0.5D0

Parameters used in line search based on the Wolfe conditions. (bfgs only)


keywords used only in NEB and SMD calculations
num_of_images 
INTEGER 
Default: 
0

Number of points used to discretize the path (it must be larger than 3).

opt_scheme 
CHARACTER 
Default: 
'quickmin'

Specify the type of optimization scheme:
'sd' : steepest descent
'broyden' : quasiNewton Broyden's second method (suggested)
'quickmin' : an optimisation algorithm based on the projected velovity Verlet scheme
'langevin' : finite temperature langevin dynamics of the string (smd only). It is used to compute the average path and the freeenergy profile.

CI_scheme 
CHARACTER 
Default: 
'noCI'

Specify the type of Climbing Image scheme:
'noCI' : climbing image is not used
'auto' : original CI scheme. The image highest in energy does not feel the effect of springs and is allowed to climb along the path
'manual' : images that have to climb are manually selected. See also CLIMBING_IMAGES card

first_last_opt 
LOGICAL 
Default: 
.FALSE.

Also the first and the last configurations are optimised "on the fly" (these images do not feel the effect of the springs).

temp_req 
REAL 
Default: 
0.D0 Kelvin

Temperature used for the langevin dynamics of the string.

ds 
REAL 
Default: 
1.D0

Optimisation step length ( Hartree atomic units ). If opt_scheme="broyden", ds is used as a guess for the diagonal part of the Jacobian matrix.

k_max, k_min

REAL 
Default: 
0.1D0 Hartree atomic units

Set them to use a Variable Elastic Constants scheme elastic constants are in the range [ k_min, k_max ] this is useful to rise the resolution around the saddle point.

path_thr 
REAL 
Default: 
0.05D0 eV / Angstrom

The simulation stops when the error ( the norm of the force orthogonal to the path in eV/A ) is less than path_thr.

use_masses 
LOGICAL 
Default: 
.FALSE.

If. TRUE. the optimisation of the path is performed using massweighted coordinates.

use_freezing 
LOGICAL 
Default: 
.FALSE.

If. TRUE. the images are optimised according to their error: only those images with an error larger than half of the largest are optimised. The other images are kept frozen.


keywords used only in metadynamics calculations
( see also the card COLLECTIVE_VARS )
fe_step(i), i=1,ncolvar 
REAL 
Default: 
0.04

Metadynamics step length (in principle different for each collective variable), defined using the same units used to define the collective variables themselves. The step also defines the spread of the Gaussianlike bias potential.

g_amplitude 
REAL 
Default: 
0.005 Hartree

Amplitude of the gaussians used in metadynamics.

fe_nstep 
INTEGER 
Default: 
100

Maximum number of steps used to evaluate the potential of mean force.

sw_nstep 
INTEGER 
Default: 
10

Number of steps used to switch to the new values of the collective variables.




Namelist: CELL 
input this namelist only if calculation = 'vcrelax', 'vcmd'
cell_dynamics 
CHARACTER 
Specify the type of dynamics for the cell. For different type of calculation different possibilities are allowed and different default values apply:
CASE ( calculation = 'vcrelax' ) 'none': default 'sd': steepest descent ( not implemented ) 'damppr': damped (Beeman) dynamics of the ParrinelloRahman extended lagrangian 'dampw': damped (Beeman) dynamics of the new Wentzcovitch extended lagrangian 'bfgs': new BFGS quasinewton algorithm, based on the trust radius procedure, is used for structural relaxation (experimental), ion_dynamics must be 'bfgs' too CASE ( calculation = 'vcmd' ) 'none': default 'pr': (Beeman) molecular dynamics of the ParrinelloRahman extended lagrangian 'w': (Beeman) molecular dynamics of the new Wentzcovitch extended lagrangian

press 
REAL 
Default: 
0.D0

Target pressure [KBar] in a variablecell md or relaxation run.

wmass 
REAL 
Default: 
0.75*Tot_Mass/pi**2 for ParrinelloRahman MD;
0.75*Tot_Mass/pi**2/Omega**(2/3) for Wentzcovitch MD

Fictitious cell mass [amu] for variablecell simulations (both 'vcmd' and 'vcrelax')

cell_factor 
REAL 
Default: 
1.2D0

Used in the construction of the pseudopotential tables. It should exceed the maximum linear contraction of the cell during a simulation.

press_conv_thr 
REAL 
Default: 
0.5D0 Kbar

Convergence threshold on the pressure for variable cell relaxation ('vcrelax' : note that the other convergence thresholds for ionic relaxation apply as well).

cell_dofree 
CHARACTER 
Default: 
'all'

Select which of the cell parameters should be moved:
all = all axis and angles are propagated volume = the cell is simply rescaled, without changing the shape x = only the x axis is moved y = only the y axis is moved z = only the z axis is moved xy = only the x and y axis are moved, angles are unchanged xz = only the x and z axis are moved, angles are unchanged yz = only the y and z axis are moved, angles are unchanged xyz = x, y and z axis are moved, angles are unchanged xyt = x1, x2, y2 (i.e. lower xy triangle of the 2 vectors) xys = x1, y1, x2, y2 (i.e. xy square of the 2 vectors) xyzt = x1, x2, y2, x3, y3, z3 (i.e. lower xyz triangle of the 3 vectors)



Namelist: PHONON 
input this namelist only in calculation = 'phonon'
modenum 
INTEGER 
Default: 
0

For singlemode phonon calculation : modenum is the index of the irreducible representation (irrep) into which the reducible representation formed by the 3*nat atomic displacements are decomposed in order to perform the phonon calculation.

xqq(i), i=1,3 
REAL 
qpoint (units 2pi/a) for phonon calculation.



Card: ATOMIC_SPECIES 
Syntax:
ATOMIC_SPECIES

Description of items:
X 
CHARACTER 
label of the atom

Mass_X 
REAL 
mass of the atomic species [amu: mass of C = 12] not used if calculation='scf','nscf', 'bands', 'phonon'

PseudoPot_X 
CHARACTER 
File containing PP for this species.
The pseudopotential file is assumed to be in the new UPF format. If it doesn't work, the pseudopotential format is determined by the file name:
*.vdb or *.van Vanderbilt US pseudopotential code *.RRKJ3 Andrea Dal Corso's code (old format) none of the above old PWscf normconserving format



Card: ATOMIC_POSITIONS { alat  bohr  angstrom  crystal
} 
IF calculation != 'neb' AND calculation != 'smd' :
Syntax:
ATOMIC_POSITIONS { alat  bohr  angstrom  crystal
}

ELSEIF calculation = 'neb' OR calculation = 'smd' :
There are at least two groups of cards, each group is composed by an identifier followed by "nat" lines as specified above:
identifier X x y z { if_pos(1) if_pos(2) if_pos(3) }
The first group ( identifier="first_image" ) contains the first image; the last group ( identifier="last_image" ) contains the last image.
There is also the possibility of specifying intermediate images; in this case their coordinates must be set between the first_image and the last_image ( identifier="intermediate_image", followed by "nat" position lines ).
IMPORTANT: Several intermediate images may be specified via intermediate_image identifier, but the total number of configurations specified in the input file must be less than num_of_images (as specified in &IONS). The initial path is obtained interpolating between the specified configurations so that all images are equispaced (only the coordinates of the first and last images are not changed).
Syntax:
ATOMIC_POSITIONS { alat  bohr  angstrom  crystal
} first_image
X(1)

x(1)

y(1)

z(1)

{ 
if_pos(1)(1)

if_pos(2)(1)

if_pos(3)(1)

} 
X(2)

x(2)

y(2)

z(2)

{ 
if_pos(1)(2)

if_pos(2)(2)

if_pos(3)(2)

} 
. . . 
X(nat)

x(nat)

y(nat)

z(nat)

{ 
if_pos(1)(nat)

if_pos(2)(nat)

if_pos(3)(nat)

} 
{ intermediate_image
X(1)

x(1)

y(1)

z(1)

X(2)

x(2)

y(2)

z(2)

. . . 
X(nat)

x(nat)

y(nat)

z(nat)

} last_image
X(1)

x(1)

y(1)

z(1)

X(2)

x(2)

y(2)

z(2)

. . . 
X(nat)

x(nat)

y(nat)

z(nat)




Description of items:
alat : atomic positions are in cartesian coordinates, in units of the lattice parameter "a" (default)
bohr : atomic positions are in cartesian coordinate, in atomic units (i.e. Bohr)
angstrom: atomic positions are in cartesian coordinates, in Angstrom
crystal : atomic positions are in crystal coordinates, i.e. in relative coordinates of the primitive lattice vectors (see below)
X 
CHARACTER 
label of the atom as specified in ATOMIC_SPECIES

x, y, z

REAL 
atomic positions

if_pos(1), if_pos(2), if_pos(3)

INTEGER 
Default: 
1

component i of the force for this atom is multiplied by if_pos(i), which must be either 0 or 1. Used to keep selected atoms and/or selected components fixed in metadynamics, neb, smd, MD dynamics or structural optimization run.



Card: K_POINTS { tpiba  automatic  crystal  gamma
} 
IF tpiba OR crystal :
Syntax:
K_POINTS tpiba  crystal nks

ELSEIF automatic :
ELSEIF gamma :


Description of items:
tpiba : read kpoints in cartesian coordinates, in units of 2 pi/a (default)
automatic: automatically generated uniform grid of kpoints, i.e, generates ( nk1, nk2, nk3 ) grid with ( sk1, sk2, sk3 ) offset. nk1, nk2, nk3 as in MonkhorstPack grids k1, k2, k3 must be 0 ( no offset ) or 1 ( grid displaced by half a grid step in the corresponding direction ) BEWARE: only grids having the full symmetry of the crystal work with tetrahedra. Some grids with offset may not work.
crystal : read kpoints in crystal coordinates, i.e. in relative coordinates of the reciprocal lattive vectors
gamma : use k = 0 (no need to list kpoint specifications after card) In this case wavefunctions can be chosen as real, and specialized subroutines optimized for calculations at the gamma point are used (memory and cpu requirements are reduced by approximately one half).
nks 
INTEGER 
Number of supplied special kpoints.

xk_x, xk_y, xk_z, wk

REAL 
Special kpoints (xk_x/y/z) in the irreducible Brillouin Zone of the lattice (with all symmetries) and weights (wk) See the literature for lists of special points and the corresponding weights.
If the symmetry is lower than the full symmetry of the lattice, additional points with appropriate weights are generated.
In a nonscf calculation, weights do not affect the results. If you just need eigenvalues and eigenvectors (for instance, for a bandstructure plot), weights can be set to any value (for instance all equal to 1).

nk1, nk2, nk3

INTEGER 
These parameters specify the kpoint grid (nk1 x nk2 x nk3) as in MonkhorstPack grids.

sk1, sk2, sk3

INTEGER 
The grid offests; sk1, sk2, sk3 must be 0 ( no offset ) or 1 ( grid displaced by half a grid step in the corresponding direction ).



Card: CELL_PARAMETERS { cubic  hexagonal
} 
Optional card, needed only if ibrav = 0 is specified, ignored otherwise !
Syntax:
CELL_PARAMETERS { cubic  hexagonal
}

Description of items:
Flag "cubic" or "hexagonal" specify if you want to look for symmetries derived from the cubic symmetry group (default) or from the hexagonal symmetry group (assuming c axis as the z axis, a axis along the x axis).
v1, v2, v3

REAL 
Crystal lattice vectors: v1(1) v1(2) v1(3) ... 1st lattice vector v2(1) v2(2) v2(3) ... 2nd lattice vector v3(1) v3(2) v3(3) ... 3rd lattice vector
In alat units if celldm(1) was specified or in a.u. otherwise.



Card: CLIMBING_IMAGES 
Optional card, needed only if CI_scheme = 'manual', ignored otherwise !
Syntax:
CLIMBING_IMAGES index1, index2, ... indexN

Description of items:
index1, index2, ... indexN

INTEGER 
index1, index2, ..., indexN are indices of the images to which the ClimbingImage procedure apply. If more than one image is specified they must be separated by a comma.



Card: CONSTRAINTS 
Optional card, used for constrained dynamics or constrained optimisations !
When this card is present the SHAKE algorithm is automatically used.
Syntax:
CONSTRAINTS nconstr { constr_tol }

Description of items:
nconstr 
INTEGER 
Number of constraints.

constr_tol 
REAL 
Tolerance for keeping the constraints satisfied.

constr_type 
CHARACTER 
Type of constrain :
'type_coord' : constraint on global coordinationnumber, i.e. the average number of atoms of type B surrounding the atoms of type A. The coordination is defined by using a FermiDirac. (four indexes must be specified).
'atom_coord' : constraint on local coordinationnumber, i.e. the average number of atoms of type A surrounding a specific atom. The coordination is defined by using a FermiDirac. (four indexes must be specified).
'distance' : constraint on interatomic distance (two atom indexes must be specified).
'planar_angle' : constraint on planar angle (three atom indexes must be specified).
'torsional_angle' : constraint on torsional angle (four atom indexes must be specified).
'bennett_proj' : constraint on the projection onto a given direction of the vector defined by the position of one atom minus the center of mass of the others. ( Ch.H. Bennett in Diffusion in Solids, Recent Developments, Ed. by A.S. Nowick and J.J. Burton, New York 1975 ).

constr(1), constr(2), constr(3), constr(4)


These variables have different meanings for different constraint types:
'type_coord' : constr(1) is the first index of the atomic type involved constr(2) is the second index of the atomic type involved constr(3) is the cutoff radius for estimating the coordination constr(4) is a smoothing parameter
'atom_coord' : constr(1) is the atom index of the atom with constrained coordination constr(2) is the index of the atomic type involved in the coordination constr(3) is the cutoff radius for estimating the coordination constr(4) is a smoothing parameter
'distance' : atoms indices object of the constraint, as they appear in the 'ATOMIC_POSITION' CARD
'planar_angle', 'torsional_angle' : atoms indices object of the constraint, as they appear in the 'ATOMIC_POSITION' CARD (beware the order)
'bennett_proj' : constr(1) is the index of the atom whose position is constrained. constr(2:4) are the three coordinates of the vector that specifies the constraint direction.

constr_target 
REAL 
Target for the constrain ( angles are specified in degrees ). This variable is optional.



Card: COLLECTIVE_VARS 
Optional card, used for metadynamics calculations !
Syntax:
COLLECTIVE_VARS ncolvar { colvar_tol }

Description of items:
ncolvar 
INTEGER 
Number of collective variables.

colvar_tol 
REAL 
Tolerance used for SHAKE.



Card: OCCUPATIONS 
Optional card, used only if occupations = 'from_input', ignored otherwise !
Syntax:
OCCUPATIONS

Description of items:
f_inp1 
REAL 
Occupations of individual states. For spinpolarized calculation, these are majority spin states.

f_inp2 
REAL 
Occupations of minority spin states for spinpolarized calculation; specify only for spinpolarized calculation.




This file has been created by helpdoc utility.
