TABLE OF CONTENTS
INTRODUCTION
&INPUTPP
prefix | outdir | filplot | plot_num | spin_component | spin_component | emin | emax | delta_e | degauss_ldos | sample_bias | kpoint | kband | lsign | spin_component | emin | emax | 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.
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 a selected wavefunction 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.
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IF plot_num=0 :
Options for total charge (plot_num=0):
spin_component |
INTEGER |
Default: |
0
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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
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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
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upper boundary of energy grid (in eV).
If not specified, LDOS is computed just for energy emin
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delta_e |
REAL |
Default: |
0.1
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Status: |
OPTIONAL
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spacing of energy grid (in eV).
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degauss_ldos |
REAL |
Default: |
degauss (converted to eV)
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Status: |
OPTIONAL
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broadening of energy levels for LDOS (in eV).
Defaults to broadening degauss specified for electronic smearing
in pw.x calculation.
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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 to be plotted
LSDA:
k-point and spin polarization to be plotted
(spin-up and spin-down correspond to different k-points!)
When both kpoint(1) and kpoint(2) are specified, all
kpoints in the range [kpoint(1),kpoint(2)] are plotted.
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kband(i), i=1,2 |
INTEGER |
Band to be plotted.
When both kband(1) and kband(2) are specified, all
bands in the range [kband(1),kband(2)] are plotted.
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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
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Status: |
OPTIONAL
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Noncollinear case only:
plot the contribution of the given state to the charge
or to the magnetization along the direction indicated
by spin_component:
0 = charge (default),
1 = x,
2 = y,
3 = z.
Ignored in unpolarized or LSDA case
When both spin_component(1) and spin_component(2) are specified,
all components in the range [spin_component(1),spin_component(2)]
are plotted.
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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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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 = format suitable for contour.x (2D)
2 = format suitable for plotrho (2D)
3 = format suitable for XCRYSDEN (2D or user-supplied 3D region)
4 = format suitable for gOpenMol (3D)
(formatted: convert to unformatted *.plt)
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:
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:
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 (presently only
if output_format = 4, i.e. gopenmol format) - works only
if the crystal axis are parallel to xyz
- 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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