PLOTGRID

Purpose

An object representing an evenly spaced rectilinear grid used for making plots

Synopsis

The PLOTGRID is comprised mainly of three axis directions. The number of points along the x-axis of the plot is given, while the number of points along remaining axes are derived so that the points are evenly spaced.

Normally a plotgrid will be two dimensional, but three dimensional plots can also be represented.

There are also datum stored representing the kind of plot the grid is for; and if an orbital based plot is desired, the index of the orbital desired for plotting.

It is also possible to define a PLOTGRID relative to specific ATOM positions, or relative to a CRYSTAL axis system.

A plotgrid should never be used until the update routine has been called. Modules which call PLOTGRID always ensure that this is done.

Default input data order

There is no associated PLOTGRIDVEC type; an input data order has not been defined.

Listing of keywords

centre= REALVEC(3)

Read the center position of the plot

  • The default is (0,0,0)

  • See x_width=, y_width= or z_width= to specify the plot widths

  • See x_points= to specify the number of points desired on the x axis

  • The number of points on the remaining axes are evaluated from their widths and the condition that the points are evenly spaced.

centre_atom= INT

Read the index of the center atom of the plot

  • To fully define all the parameters of the plotgrid, the user must supply ATOMVEC information

  • See the update routine

crystal_plane= REALVEC(3)

Read the desired crystal plane for plotting

  • This is equivalent to the z_axis= keyword

  • It should only be used when the kind of the is crystal

  • Refer to the kind= keyword

kind= STR

Read the kind of plot the grid represents

  • The default is the blank string

  • The allowed kinds are:

    electron_density,
    laplacian_density,
    orbital_density,
    orbital,
    difference_density,
    fermi_mobility,
    crystal_error_map,
    qq_plot,
    spin_density,
    current_density,
    j_density,
    jp_density,
    jd_density,
    elf,
    electric_potential,
    solenoidal_jp

  • The laplacian_density is a plot of 2 ρ

  • The difference density is a plot of ρ- ρpromol where ρpromol is evaluated as a sum of spherically averaged atomic UHF densities calculated in the same basis set

  • fermi_mobility is a plot of Luken's fermi mobility function

  • crystal_error_map is a plot of the inverse fourier synthesis of the differences between the calculated and (phased) observed structure factors of the electron density

  • qq_plot is a plot of the ranked sigma-normalised deviations of predicted and observed structure factor magnitudes plotted against those expected from a normal distribution; also known as an Abraham-Skeev plot

  • current_density and j_density are equivalent; a general complex density matrix must exist

  • jp_density is a plot of the paramagnetic current density

  • jd_density is a plot of the diamagnetic current density

  • elf is a plot of the electron localisation function

  • solenoidal_jp is a plot of the solenoidal part of the paramagnetic current density

maximum_cell_distance= REAL

Read the maximum cell distance for a crystal-section plot

  • The default is 5

  • This is currently only used with crystal_error_map plots.

max_cell_distance= REAL

Equivalent to maximum_cell_distance=

normal= REALVEC(3)

Equivalent to z_axis= or crystal_plane=

orbital= INT

Read in the integer of the orbital to be used in an orbital-type plot

  • Must be greater than 0

put

Print out information about the PLOTGRID to the stdout file in human readable form

type= STR

Equivalent to kind=

units= STR

Read a string which describes the units of the next inputted numerical entity; that is, the next real or complex number, real or complex vector, or real or complex matrix.

  • The default atomic units are restored after the numerical entity has been inputted

  • Warning: if the next inputted datum is not a numerical entity, the new units keyword remains in force

x_axis= REALVEC(3)

Read in the x-axis direction of the plot

  • The default is (1,0,0)

  • Note: the default can have different interpretation in a crystal axis system

  • Note: if z_axis= is defined, then the x axis is orthogonalised to the entered z axis of the plot.

x_axis_atoms= INTVEC(2)

Read in the indices of two atoms which lie along the x-axis

  • To evaluate all data in the PLOTGRID some ATOMVEC information must be supplied

  • Refer to the update routine

x_axis_offset= REAL

Read a number with which to displace the PLOTGRID along the x-axis

  • The default is 0

x_points= INT

Read in the number of points wanted along the x-axis

  • The default is 51

  • The number of points should be odd; if not, the plot grid will increase the even number by one

  • The number of points on the remaining axes are evaluated from their widths and the condition that the points are evenly spaced.

  • See y_width= or z_width= to specify the plot widths

  • The number of points on the y and z axes is also made to be odd; thus the center of the plot corresponds exactly to a grid point

x_width= REAL

Specify the width of the plot along the x axis

  • The default is 2

  • The value is used to calculate the spacing of the points along the x axis

  • The total number of points in the plot is evaluade from the remaining widths of the plot, assuming even spacing

  • See y_width= and z_width=

y_axis= REALVEC(3)

Read the direction of the y axis of the plot

  • The default is (0,1,0)

  • Note: the default can have different interpretation in a crystal axis system

  • Note: if the y axis is not orthogonal to the x axis, then it is orthogonalised to the x axis

  • Note: if z_axis= is defined, then the y axis is set to the cross product of the z axis and the orthogonalised x axis of the plot

y_axis_atoms= INTVEC(2)

Read in the indices of two atoms which lie along the y-axis

  • To evaluate all data in the PLOTGRID some ATOMVEC information must be supplied

  • Refer to the update routine

y_axis_offset= REAL

Read a number with which to displace the PLOTGRID along the y-axis

  • The default is 0

y_width= REAL

Specify the width of the plot along the y axis

  • The default is 2

  • The value is used to calculate the number of points along the y axis, and the total number of points in the grid

  • Refer to x_width= and x_points=

z_axis= REALVEC(3)

Read the direction of the z axis of the plot

  • The default is (0,0,1)

  • Note: the default can have different interpretation in a crystal axis system

  • If this keyword is used, the y axis is set to the cross product of the z axis and the orthogonalised x axis of the plot

z_axis_offset= REAL

Read a number with which to displace the PLOTGRID along the z-axis

  • The default is 0

z_width= REAL

Specify the width of the plot along the z axis

  • The default is 0

  • This is used to calculate the number of points along the z axis, and the total number of points in the grid

  • Refer to x_width= and x_points=