TABLE OF CONTENTS
INTRODUCTION
&INPUTPP
prefix | outdir | filplot | plot_num | spin_component | spin_component | emin | emax | delta_e | degauss_ldos | use_gauss_ldos | sample_bias | kpoint | kband | lsign | spin_component | emin | emax | spin_component | spin_component | spin_component | spin_component
&PLOT
nfile | filepp | weight | iflag | output_format | fileout | interpolation | e1 | x0 | nx | e1 | e2 | x0 | nx | ny | e1 | e2 | e3 | x0 | nx | ny | nz | radius | nx | ny
INTRODUCTION
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
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| prefix |
CHARACTER |
prefix of files saved by program pw.x
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| outdir |
CHARACTER |
| Default: |
value of the ESPRESSO_TMPDIR environment variable if set;
current directory ('./') otherwise
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directory containing the input data, i.e. the same as in pw.x
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| filplot |
CHARACTER |
file "filplot" contains the quantity selected by plot_num
(can be saved for further processing)
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| plot_num |
INTEGER |
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)
123 = DORI: density overlap regions indicator
(doi: 10.1021/ct500490b) Implemented by D. Yang & Q.Liu
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IF plot_num = 0 or 9 :|
Options for total charge (plot_num=0)
or for total minus atomic charge (plot_num=9):
| spin_component |
INTEGER |
| Default: |
0
|
0 = total charge (default value),
1 = spin up charge,
2 = spin down charge.
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ELSEIF plot_num=1 :|
Options for total potential (plot_num=1):
| spin_component |
INTEGER |
| Default: |
0
|
0 = spin averaged potential (default value),
1 = spin up potential,
2 = spin down potential.
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ELSEIF plot_num=3 :|
Options for LDOS (plot_num=3):
LDOS is plotted on grid [emin, emax] with spacing delta_e.
| emin |
REAL |
| Default: |
e_fermi
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lower boundary of energy grid (in eV).
Defaults to Fermi energy.
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| emax |
REAL |
| Status: |
OPTIONAL
|
upper boundary of energy grid (in eV).
Defaults to Fermi energy.
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| delta_e |
REAL |
| Default: |
0.1
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| Status: |
OPTIONAL
|
spacing of energy grid (in eV).
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| degauss_ldos |
REAL |
| Default: |
degauss (converted to eV)
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| Status: |
OPTIONAL
|
broadening of energy levels for LDOS (in eV).
Defaults to broadening degauss specified for electronic smearing
in pw.x calculation.
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| use_gauss_ldos |
LOGICAL |
| Default: |
.false.
|
| Status: |
OPTIONAL
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If .true., gaussian broadening (ngauss=0) is used for LDOS calculation.
Defaults .false., in which case the broadening scheme
of the pw.x calculation will be used.
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ELSEIF plot_num=5 :|
Options for STM images (plot_num=5):
| sample_bias |
REAL |
the bias of the sample (Ry) in stm images
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ELSEIF plot_num=7 :|
Options for |psi|^2 (plot_num=7):
| kpoint(i), i=1,2 |
INTEGER |
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
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| kband(i), i=1,2 |
INTEGER |
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
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| lsign |
LOGICAL |
if true and k point is Gamma, plot |psi|^2 sign(psi)
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| spin_component(i), i=1,2 |
INTEGER |
| Default: |
0
|
| Status: |
OPTIONAL
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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
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ELSEIF plot_num=10 :|
Options for ILDOS (plot_num=10):
| emin |
REAL |
lower energy boundary (in eV)
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| emax |
REAL |
upper energy boundary (in eV),
i.e. compute ILDOS from emin to emax
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| spin_component |
INTEGER |
| Default: |
0
|
for LSDA case only: plot the contribution to ILDOS of
0 = spin-up + spin-down (default)
1 = spin-up only
2 = spin-down only
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ELSEIF plot_num=13 :|
Options for noncollinear magnetization (plot_num=13):
| spin_component |
INTEGER |
| Default: |
0
|
0 = absolute value (default value)
1 = x component of the magnetization
2 = y component of the magnetization
3 = z component of the magnetization
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ELSEIF plot_num=17 :|
Options for reconstructed charge density (plot_num=17):
| spin_component |
INTEGER |
| Default: |
0
|
0 = total charge (default value),
1 = spin up charge,
2 = spin down charge.
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ELSEIF plot_num=22 :|
Options for kinetic energy density (plot_num=22),
LSDA case only:
| spin_component |
INTEGER |
| Default: |
0
|
0 = total density (default value),
1 = spin up density,
2 = spin down density.
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Namelist: &PLOT
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| nfile |
INTEGER |
| Default: |
1
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| Status: |
OPTIONAL
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the number of data files to read
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| filepp(i), i=1,nfile |
CHARACTER |
| Default: |
filepp(1)=filplot
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nfile = 1 : file containing the quantity to be plotted
nfile > 1 : see weight
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| weight(i), i=1,nfile |
REAL |
| Default: |
weight(1)=1.0
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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) + ...
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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
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| iflag |
INTEGER |
0 = 1D plot of the spherical average
1 = 1D plot
2 = 2D plot
3 = 3D plot
4 = 2D polar plot on a sphere
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| output_format |
INTEGER |
(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)
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| fileout |
CHARACTER |
| Default: |
standard output
|
name of the file to which the plot is written
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| interpolation |
CHARACTER |
| Default: |
'fourier'
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Type of interpolation:
- 'fourier'
- 'bspline' :
(EXPERIMENTAL)
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IF iflag = 0 or 1 :|
the following variables are REQUIRED:
| e1(i), i=1,3 |
REAL |
3D vector which determines the plotting line (in alat units)
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| x0(i), i=1,3 |
REAL |
3D vector, origin of the line (in alat units)
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| nx |
INTEGER |
number of points in the line:
rho(i) = rho( x0 + e1 * (i-1)/(nx-1) ), i=1, nx
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ELSEIF iflag = 2 :|
the following variables are REQUIRED:
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e1(i),
e2(i),
i=1,3 |
REAL |
3D vectors which determine the plotting plane (in alat units)
BEWARE: e1 and e2 must be orthogonal
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| x0(i), i=1,3 |
REAL |
3D vector, origin of the plane (in alat units)
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nx, ny |
INTEGER |
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
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ELSEIF iflag = 3 :|
the following variables are OPTIONAL:
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e1(i),
e2(i),
e3(i),
i=1,3 |
REAL |
3D vectors which determine the plotting parallelepiped
(if present, must be orthogonal)
e1, e2, and e3 are in alat units !
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| x0(i), i=1,3 |
REAL |
3D vector, origin of the parallelepiped
x0 is in alat units !
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nx, ny, nz |
INTEGER |
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 output_format = 3 (XCRYSDEN), the above variables
are used to determine the grid to plot.
- If 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 e1, e2, e3, x0 are present,
and e1, e2, e3 are parallel to xyz
and parallel to crystal axis, a subset of the FFT
grid that approximately covers the parallelepiped
defined by e1, e2, e3, x0, is
written - untested, might be obsolete
- Otherwise, the required 3D grid is generated from the
Fourier components (may be VERY slow)
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ELSEIF iflag = 4 :|
the following variables are REQUIRED:
| radius |
REAL |
Radius of the sphere (alat units), centered at (0,0,0)
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nx, ny |
INTEGER |
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
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