Programs display_densities - display of the superstructure
and excitations
The program display_densities
can be used simply to popout spin/exchange field configuration
and also to display a 3d animation of spin/moment/densities, even including a movie of
excitations.
Figure 18:
Calculated Spin-Structure of NdCu
at
1.5 K and
.
[plot created by program display_densities]
|
- display_densities -f[c 12 0.1] mcphas.sps T Ha Hb Hc
-
- display_densities -f mcphas.sps x y
-
- display_densities -f mcphas.sps n
- if used with -f filename this file has to be a mcphas.mf or mcphas.sps or mcphas.tst file,
the spin configuration
at given temperature T[K] and magnetic effective field H[T]
is read and extracted from this file and printed on screen (stdout), nothing
else is done. Insterad of temperature and magnetic field also the x y point coordinates
in the phasediagram or the index n (from the sequence of spin configuartions) can be given.
the option -fc 12 0.1 displays a commented user readable information about the 12 largerst
spin components in the primitive unit cell with absolute values larger than 0.1 (useful for
inspection of numbers).
- display_densities -tMSL -prefix 001 T Ha Hb Hc
-
- display_densities -tHex -prefix 001T Ha Hb Hc
-
- display_densities -tI -prefix 001T Ha Hb Hc
- if used with -t... output to stdout a table with T Ha Hb Hc atom positions and
for -tMSL
magnetic moments
, orbital moments and spin
of each atom in the magnetic unitc cell , for
-tHex exchange fields and for
-tI with expectation values of interaction operators
.
- display_densities -c
-s
-o
-m
-j-p i j k
-div-S
-L
-M-P-prefix 001T Ha Hb Hc [h k l E]
-
- display_densities -c
-s
-o
-m
-j-p i j k
-div-S
-L
-M-P-prefix 001x y
- if used without a filename, the information is read from results/mcphas.* res
ults/mcdisp.*
output files and 3d graphical animations are created.
options are:
-c ... calculate chargedensity
-s ... calculate spindensity
-o ... calculate angular orbital momentum density
-m ... calculate magnetic moment density
-j ... calculate currentdensity
-p i j k ... calculate projection of spin/orbital/current/magnetic moment density
along direction i j k, e.g. 0 0 1
-div ... calculate divergence of spin/orbital/current/magnetic moment density
-S ... show arrow indicating spin
-L ... show arrow indicating orbital angular momentum
-M ... show arrow indicating magnetic moment
-P ... calculate phononic displacement
note, that in order to animate changes in the above quantities, the corresponding
switch has to be enabled in the mcdisp calculation (mcdisp.par) and the single ion
modules have to be capable of calculating the corresponding observables.
-prefix 001 ... use input file(s) results/001mc* instead of results/mc*
examples:
display_densities -c 2 0 0 1
...calculates the charge density at T=2K and H=(0,0,1) Tesla
display_densities -tI 2 0 0 1
... outputs a table with atomic positions and expectations values <I>
Figure 19:
Calculated 4f Charge-Structure of NdCu
at
1.5 K and
.
[plot created by program display_densities]
|
The program can be used to calculate (partial) chargedensity for the unfilled shells
of magnetic ions in a magnetic unit cell, which has been calculated by mcphas and
stored in mcphas.mf for a specific temperature and magnetic field.
For the calculation of the charge density the formula are used as given in
appendix L.
In order to do so display_densities requires input files and the result of a
full mcphas simulation.
Alternatively, display_densities
can calculate the spindensity, the orbital magnetic moment density, the total magnetic
moment density (in Trammel gauge) and the (orbital) electric current density.
The program outputs a magnetic structure (and magnetic excitation)
graphic/movie in the output files of different format:
results/spins*.eps (postscript), results/spins*.fst (fp_studio),
results/spins.out (ascii) and results/spins*.jvx (javaview).
Output files:
- encapsulated postscript ps-file results/spins*.eps
of a spin/orbital/totalmagnetic moment configuration,
- the files results/spins.fst and results/spins_prim.fst are created,
which can be read by the fullprof program fp_studio
for on screen display of a spin/orbital/totalmagnetic moment configuration,
- the configuration of expectation values
(or whatever is stored in the file addressed by the option -f)
is printed to stdout - therefore this program can be used with option -f results/mcphas.mf
to generate an input file
for program McDisp (example: spins -f results/mcphas.mf 1 1 0 0
mcdisp.mf)
- the text file results/spins.out is created, which is useful to produce input files for
the diffraction program mcdiff (done in the script setup_mcdiff_in)
- the graphics files results/spins.jvx and results/spins_prim.jvx, which can be displayed
by the program javaview, e.g. by the command java javaview spin_prim.jvx.
- if spins is used with arguments h k l E(meV), it takes the eigenvectors of magnetic
excitations
from files results/mcdisp.q* created by mcdisp) and produces a graphical
animation of the spin osciallation which is associated with this magnetic mode. The output is a series
of files results/spins.*.jvx and results/spins_prim.*.jvx which can be viewed by program
javaview, e.g. by the command java javaview "model=results/spins_prim.*.jvx"
Animation.LastKey=16 background="255 255 255". javaview is also able to produce a sequence
of gif files (press c in the animation window), which can then be processed by an animation editor
to generate an animation, which can be inserted in presentations. For example, you can use
Imagemagick graphics package (has to be installed separately!)
to create an animation. The following command will issue a proper gif animation, which you can include in
power point
presentations etc.: convert -delay 1 -size 100x100 -loop 1 geomAnim.*.gif output.gif.
Note, in case of non-orthogonal axes the convention
for applied field
is
,
and
perpendicular to
and
.
The graphics output format can be fine tuned in results/graphic_parameters.set
by spins_scale_moment,
show_abc_unitcell, show_primitive_crystal_unitcell, show_magnetic_unitcell, show_atoms,
scale_view_1,
scale_view_2, scale_view_3,
spins_wave_amplitude, spins_show_ellipses, spins_show_direction_of_static_moment.
show_abc_unitcell, show_primitive_crystal_unitcell, show_magnetic_unitcell, show_atoms,
show_density...
Technical information: the program display_densities
is actually a script which
calls spins
(a program with the same arguments as display_densities
which calculates the iso surfaces and stores
it in format for the java based graphic program javaview and
also as a grid. The way in which this is done is controlled by
the parameter file results/graphic_parameters.set
.... in order to display the results graphically the following java
programs are called:
java javaview results/spins.jvx
java javaview "model=results/spins.*.jvx" Animation.LastKey=16 background="255 255 255"