    ------------------------------------------------------------------------
    INPUT FILE DESCRIPTION

    Program: pp.x / PWscf / Quantum Espresso (version: 6.6)
    ------------------------------------------------------------------------

    Purpose of pp.x: data analysis and plotting.

    The code performs two steps:

    (1) reads the output produced by pw.x, extracts and calculates
        the desired quantity/quantities (rho, V, ...)

    (2) writes the desired quantity to file in a suitable format for
        various types of plotting and various plotting programs

    The input data of this program is read from standard input
    or from file and has the following format:

    NAMELIST &INPUTPP
       containing the variables for step (1), followed by

    NAMELIST &PLOT
       containing the variables for step (2)

    The two steps can be performed independently. In order to perform
    only step (2), leave namelist &INPUTPP blank. In order to perform
    only step (1), do not specify namelist &PLOT

    Intermediate results from step 1 can be saved to disk (see
    variable "filplot" in &INPUTPP) and later read in step 2.
    Since the file with intermediate results is formatted, it
    can be safely transferred to a different machine. This
    also allows plotting of a linear combination (for instance,
    charge differences) by saving two intermediate files and
    combining them (see variables "weight" and "filepp" in &PLOT)

    All output quantities are in ATOMIC (RYDBERG) UNITS unless
    otherwise explicitly specified.
    All charge densities integrate to the NUMBER of electrons
    not to the total charge.
    All potentials have the dimension of an energy (e*V, not V).

    ========================================================================
    NAMELIST: &INPUTPP

       +--------------------------------------------------------------------
       Variable:       prefix

       Type:           CHARACTER
       Description:    prefix of files saved by program pw.x
       +--------------------------------------------------------------------

       +--------------------------------------------------------------------
       Variable:       outdir

       Type:           CHARACTER
       Description:    directory containing the input data, i.e. the same as in pw.x
       Default:        value of the ESPRESSO_TMPDIR environment variable if set;
                       current directory ('./') otherwise
       +--------------------------------------------------------------------

       +--------------------------------------------------------------------
       Variable:       filplot

       Type:           CHARACTER
       Description:    file "filplot" contains the quantity selected by plot_num
                       (can be saved for further processing)
       +--------------------------------------------------------------------

       +--------------------------------------------------------------------
       Variable:       plot_num

       Type:           INTEGER
       Description:    Selects what to save in filplot:

                          0  = electron (pseudo-)charge density

                          1  = total potential V_bare + V_H + V_xc

                          2  = local ionic potential V_bare

                          3  = local density of states at specific energy or grid of energies
                               (number of states per volume, in bohr^3, per energy unit, in Ry)

                          4  = local density of electronic entropy

                          5  = STM images
                               Tersoff and Hamann, PRB 31, 805 (1985)

                          6  = spin polarization (rho(up)-rho(down))

                          7  = contribution of selected wavefunction(s) to the
                               (pseudo-)charge density. For norm-conserving PPs,
                               |psi|^2 (psi=selected wavefunction). Noncollinear case:
                               contribution of the given state to the charge or
                               to the magnetization along the direction indicated
                               by spin_component (0 = charge, 1 = x, 2 = y, 3 = z )

                          8  = electron localization function (ELF)

                          9  = charge density minus superposition of atomic densities

                          10 = integrated local density of states (ILDOS)
                               from "emin" to "emax" (emin, emax in eV)
                               if "emax" is not specified, "emax"=E_fermi

                          11 = the V_bare + V_H potential

                          12 = the sawtooth electric field potential (if present)

                          13 = the noncollinear magnetization.

                          17 = all-electron valence charge density
                               can be performed for PAW calculations only
                               requires a very dense real-space grid!

                          18 = The exchange and correlation magnetic field in the noncollinear case

                          19 = Reduced density gradient
                               ( J. Chem. Theory Comput. 7, 625 (2011), doi:10.1021/ct100641a )
                               Set the isosurface between 0.3 and 0.6 to plot the
                               non-covalent interactions (see also plot_num = 20)

                          20 = Product of the electron density (charge) and the second
                               eigenvalue of the electron-density Hessian matrix;
                               used to colorize the RDG plot (plot_num = 19)

                          21 = all-electron charge density (valence+core).
                               For PAW calculations only; requires a very dense real-space grid.

                          22 = kinetic energy density (for meta-GGA and XDM only)
       +--------------------------------------------------------------------

       ________________________________________________________________________
       * IF plot_num=0 :

          OPTIONS FOR TOTAL CHARGE (PLOT_NUM=0):

          +--------------------------------------------------------------------
          Variable:       spin_component

          Type:           INTEGER
          Default:        0
          Description:    0 = total charge (default value),
                          1 = spin up charge,
                          2 = spin down charge.
          +--------------------------------------------------------------------

       * ELSE IF plot_num=1 :

          OPTIONS FOR TOTAL POTENTIAL (PLOT_NUM=1):

          +--------------------------------------------------------------------
          Variable:       spin_component

          Type:           INTEGER
          Default:        0
          Description:    0 = spin averaged potential (default value),
                          1 = spin up potential,
                          2 = spin down potential.
          +--------------------------------------------------------------------

       * ELSE IF plot_num=3 :

          OPTIONS FOR LDOS (PLOT_NUM=3):
          LDOS IS PLOTTED ON GRID [EMIN, EMAX] WITH SPACING DELTA_E.

          +--------------------------------------------------------------------
          Variable:       emin

          Type:           REAL
          Default:        e_fermi
          Description:    lower boundary of energy grid (in eV).

                          Defaults to Fermi energy.
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       emax

          Type:           REAL
          Status:         OPTIONAL
          Description:    upper boundary of energy grid (in eV).

                          Defaults to Fermi energy.
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       delta_e

          Type:           REAL
          Default:        0.1
          Status:         OPTIONAL
          Description:    spacing of energy grid (in eV).
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       degauss_ldos

          Type:           REAL
          Default:        degauss (converted to eV)
          Status:         OPTIONAL
          Description:    broadening of energy levels for LDOS (in eV).

                          Defaults to broadening degauss specified for electronic smearing
                          in pw.x calculation.
          +--------------------------------------------------------------------

       * ELSE IF plot_num=5 :

          OPTIONS FOR STM IMAGES (PLOT_NUM=5):

          +--------------------------------------------------------------------
          Variable:       sample_bias

          Type:           REAL
          Description:    the bias of the sample (Ry) in stm images
          +--------------------------------------------------------------------

       * ELSE IF plot_num=7 :

          OPTIONS FOR |PSI|^2 (PLOT_NUM=7):

          +--------------------------------------------------------------------
          Variable:       kpoint(i), i=1,2

          Type:           INTEGER
          Description:    Unpolarized and noncollinear case:
                                  k-point(s) to be plotted
                          LSDA:
                                  k-point(s) and spin polarization to be plotted
                                  (spin-up and spin-down correspond to different k-points!)

                          To plot a single kpoint ikpt, specify kpoint=ikpt or kpoint(1)=ikpt
                          To plot a range of kpoints [imin, imax], specify kpoint(1)=imin and kpoint(2)=imax
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       kband(i), i=1,2

          Type:           INTEGER
          Description:    Band(s) to be plotted.

                          To plot a single band ibnd, specify kband=ibnd or kband(1)=ibnd
                          To plot a range of bands [imin, imax], specify kband(1)=imin and kband(2)=imax
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       lsign

          Type:           LOGICAL
          Description:    if true and k point is Gamma, plot |psi|^2 sign(psi)
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       spin_component(i), i=1,2

          Type:           INTEGER
          Default:        0
          Status:         OPTIONAL
          Description:    Noncollinear case only:
                          plot the contribution of the given state(s) to the charge
                          or to the magnetization along the direction(s) indicated
                          by spin_component:
                                  0 = charge (default),
                                  1 = x,
                                  2 = y,
                                  3 = z.

                          Ignored in unpolarized or LSDA case

                          To plot a single component ispin, specify spin_component=ispin or spin_component(1)=ispin
                          To plot a range of components [imin, imax], specify spin_component(1)=imin and spin_component(2)=imax
          +--------------------------------------------------------------------

       * ELSE IF plot_num=10 :

          OPTIONS FOR ILDOS (PLOT_NUM=10):

          +--------------------------------------------------------------------
          Variable:       emin

          Type:           REAL
          Description:    lower energy boundary (in eV)
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       emax

          Type:           REAL
          Description:    upper energy boundary (in eV),
                          i.e. compute ILDOS from "emin" to "emax"
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       spin_component

          Type:           INTEGER
          Default:        0
          Description:    for LSDA case only: plot the contribution to ILDOS of
                          0 = spin-up + spin-down (default)
                          1 = spin-up   only
                          2 = spin-down only
          +--------------------------------------------------------------------

       * ELSE IF plot_num=13 :

          OPTIONS FOR NONCOLLINEAR MAGNETIZATION (PLOT_NUM=13):

          +--------------------------------------------------------------------
          Variable:       spin_component

          Type:           INTEGER
          Default:        0
          Description:    0 = absolute value (default value)
                          1 = x component of the magnetization
                          2 = y component of the magnetization
                          3 = z component of the magnetization
          +--------------------------------------------------------------------

       * ELSE IF plot_num=17 :

          OPTIONS FOR RECONSTRUCTED CHARGE DENSITY (PLOT_NUM=17):

          +--------------------------------------------------------------------
          Variable:       spin_component

          Type:           INTEGER
          Default:        0
          Description:    0 = total charge (default value),
                          1 = spin up charge,
                          2 = spin down charge.
          +--------------------------------------------------------------------

       * ELSE IF plot_num=22 :

          OPTIONS FOR KINETIC ENERGY DENSITY (PLOT_NUM=22),
          LSDA CASE ONLY:

          +--------------------------------------------------------------------
          Variable:       spin_component

          Type:           INTEGER
          Default:        0
          Description:    0 = total density (default value),
                          1 = spin up density,
                          2 = spin down density.
          +--------------------------------------------------------------------

       ENDIF
       ________________________________________________________________________

    ===END OF NAMELIST======================================================

    ========================================================================
    NAMELIST: &PLOT

       +--------------------------------------------------------------------
       Variable:       nfile

       Type:           INTEGER
       Default:        1
       Status:         OPTIONAL
       Description:    the number of data files to read
       +--------------------------------------------------------------------

       ///---
          +--------------------------------------------------------------------
          Variable:       filepp(i), i=1,nfile

          Type:           CHARACTER
          Default:        filepp(1)=filplot
          Description:    nfile = 1 : file containing the quantity to be plotted
                          nfile > 1 : see "weight"
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       weight(i), i=1,nfile

          Type:           REAL
          Default:        weight(1)=1.0
          Description:    weighing factors: assuming that rho(i) is the quantity
                          read from filepp(i), the quantity that will be plotted is:

                          weight(1)*rho(1) + weight(2)*rho(2) + weight(3)*rho(3) + ...
          +--------------------------------------------------------------------

          BEWARE: atomic coordinates are read from the first file;
                  if their number is different for different files,
                  the first file must have the largest number of atoms

       \\\---

       +--------------------------------------------------------------------
       Variable:       iflag

       Type:           INTEGER
       Description:    0 = 1D plot of the spherical average
                       1 = 1D plot
                       2 = 2D plot
                       3 = 3D plot
                       4 = 2D polar plot on a sphere
       +--------------------------------------------------------------------

       +--------------------------------------------------------------------
       Variable:       output_format

       Type:           INTEGER
       Description:    (ignored on 1D plot)

                       0  = format suitable for gnuplot   (1D)

                       1  = obsolete format no longer supported

                       2  = format suitable for plotrho   (2D)

                       3  = format suitable for XCRYSDEN  (2D or user-supplied 3D region)

                       4  = obsolete format no longer supported

                       5  = format suitable for XCRYSDEN  (3D, using entire FFT grid)

                       6  = format as gaussian cube file  (3D)
                            (can be read by many programs)

                       7  = format suitable for gnuplot   (2D) x, y, f(x,y)
       +--------------------------------------------------------------------

       +--------------------------------------------------------------------
       Variable:       fileout

       Type:           CHARACTER
       Default:        standard output
       Description:    name of the file to which the plot is written
       +--------------------------------------------------------------------

       +--------------------------------------------------------------------
       Variable:       interpolation

       Type:           CHARACTER
       Default:        'fourier'
       Description:
                       Type of interpolation:
                            'fourier'

                       'bspline' :
                            (EXPERIMENTAL)
       +--------------------------------------------------------------------

       ________________________________________________________________________
       * IF iflag = 0 or 1 :

          THE FOLLOWING VARIABLES ARE REQUIRED:

          +--------------------------------------------------------------------
          Variable:       e1(i), i=1,3

          Type:           REAL
          Description:    3D vector which determines the plotting line (in alat units)
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       x0(i), i=1,3

          Type:           REAL
          Description:    3D vector, origin of the line (in alat units)
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       nx

          Type:           INTEGER
          Description:    number of points in the line:

                          rho(i) = rho( x0 + e1 * (i-1)/(nx-1) ), i=1, nx
          +--------------------------------------------------------------------

       * ELSE IF iflag = 2 :

          THE FOLLOWING VARIABLES ARE REQUIRED:

          +--------------------------------------------------------------------
          Variables:      e1(i), e2(i), i=1,3

          Type:           REAL
          Description:    3D vectors which determine the plotting plane (in alat units)

                          BEWARE: @b e1 and @b e2 must be orthogonal
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       x0(i), i=1,3

          Type:           REAL
          Description:    3D vector, origin of the plane (in alat units)
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variables:      nx, ny

          Type:           INTEGER
          Description:    Number of points in the plane:

                          rho(i,j) = rho( x0 + e1 * (i-1)/(nx-1)
                                          + e2 * (j-1)/(ny-1) ), i=1,nx ; j=1,ny
          +--------------------------------------------------------------------

       * ELSE IF iflag = 3 :

          THE FOLLOWING VARIABLES ARE OPTIONAL:

          +--------------------------------------------------------------------
          Variables:      e1(i), e2(i), e3(i), i=1,3

          Type:           REAL
          Description:    3D vectors which determine the plotting parallelepiped
                          (if present, must be orthogonal)

                          @ref e1, @ref e2, and @ref e3 are in alat units !
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variable:       x0(i), i=1,3

          Type:           REAL
          Description:    3D vector, origin of the parallelepiped

                          "x0" is in alat units !
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variables:      nx, ny, nz

          Type:           INTEGER
          Description:    Number of points in the parallelepiped:

                          rho(i,j,k) = rho( x0 + e1 * (i-1)/nx
                                            + e2 * (j-1)/ny
                                            + e3 * (k-1)/nz ),
                                       i = 1, nx ; j = 1, ny ; k = 1, nz

                          - If @ref output_format = 3 (XCRYSDEN), the above variables
                            are used to determine the grid to plot.

                          - If @ref output_format = 5 (XCRYSDEN), the above variables
                            are ignored, the entire FFT grid is written in the
                            XCRYSDEN format - works for any crystal axis (VERY FAST)

                          - If @ref e1, @ref e2, @ref e3, @ref x0 are present,
                            and @ref e1, @ref e2, @ref e3 are parallel to xyz
                            and parallel to crystal axis, a subset of the FFT
                            grid that approximately covers the parallelepiped
                            defined by @ref e1, @ref e2, @ref e3, @ref x0, is
                            written - untested, might be obsolete

                          - Otherwise, the required 3D grid is generated from the
                            Fourier components (may be VERY slow)
          +--------------------------------------------------------------------

       * ELSE IF iflag = 4 :

          THE FOLLOWING VARIABLES ARE REQUIRED:

          +--------------------------------------------------------------------
          Variable:       radius

          Type:           REAL
          Description:    Radius of the sphere (alat units), centered at (0,0,0)
          +--------------------------------------------------------------------

          +--------------------------------------------------------------------
          Variables:      nx, ny

          Type:           INTEGER
          Description:    Number of points in the polar plane:

                          phi(i)   = 2 pi * (i - 1)/(nx-1), i=1, nx
                          theta(j) =   pi * (j - 1)/(ny-1), j=1, ny
          +--------------------------------------------------------------------

       ENDIF
       ________________________________________________________________________

    ===END OF NAMELIST======================================================

    This file has been created by helpdoc utility on Wed Dec 02 08:04:45 CET 2020