XCrySDen only visualizes
Fermi surfaces. This means it is user responsibility to
calculate eigenvalues in the irreducible wedge of
Brillouin zone (IBZ). These IBZ eigenvalues should then
be generated over the whole BZ, and stored in proper
format, which is called Band XSF (BXSF). The BXSF file
can contain the eigenvalues of an arbitrary number of
bands.
Here you can find
all the details about the BXSF format. Once the BXSF
file is constructed load it as
xcrysden --bxsf
file.bxsf or use the
File-->Open Structure ...-->Open BXSF
(i.e. Fermi surface files) . In a while
the Fermi surface will be displayed in a viewer window.
Actually, the viewer is composed from notebook, holding
the corresponding Fermi surfaces of particular bands in
separate pages.
Note for WIEN users:
XCrySDen can
automatically calculate the eigenvalues using the WIEN
program, and generate the BXSF file. Please find more
informations
here.
Fermi surface viewer is composed from several
pages, each holding a Fermi surface of particular band.
In bellow figure, we see three tabs (i.e. Band #1, Band
#2, and Band #3) aimed at switching between different
pages. At the top of each page a top-toolbox is
located. The left-toolbox is located on the left side,
while on the bottom we have a status frame.
From the
version 1.4 on the XCrySDen can display
the Fermi surfaces of all the bands together (i.e.
multi-band display of Fermi surface). This option is
accessed on the last (right-most) page.
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Degree of Interpolation
The degree
of interpolation can be set with the
scale-widget. Press the [Submit] for
performing the interpolation (it takes some time).
The interpolation is the so-called LCASI
interpolation, which gives superior results to
spline interpolation, since it quenches the
oscillations. Use this feature to improve the
quality of surfaces.
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Zoom step
The zoom-step can be set with scale-widget.
Pressing [+] button enlarges Fermi surface,
while the [-] button shrinks the Fermi
surface by zoom-step amount.
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Revert Sides
Reverts the front and back sides of the surface,
i.e., front-side becomes back-side and
vice-versa.
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Revert Normals
Use this button when the illumination of the Fermi
surface is odd.
Here you can
read more details about the
Revert Sides/Revert
Normals issues.
There are seven buttons located on the
left-toolbox. Their function is the following:
-- displays Fermi surface in
Brillouin zone (BZ)
-- displays Fermi
surface in reciprocal unit cell
-- toggles the cropping
of Fermi surface to BZ
-- toggles the
display of the BZ and reciprocal unit cell frames
-- displays the BZ and reciprocal
unit cell in wireframe mode
-- displays the BZ and reciprocal
unit cell in transparent-solid mode
-- displays the BZ and
reciprocal unit cell in transparent-solid +
wireframe mode
Status frame is located on the bottom of each
page. On the left side of the status frame the
following informations are displayed: Fermi energy,
minimum eigenvalue of the current band, and maximum
eigenvalue of the current band. On the right side of
the status frame the
Isolevel: [ ] entry is
located where one can set the isovalue of the
isosurface to display (hence can be different from
Fermi level).
The Fermi surface viewer does not use conventional
menus. Instead it uses the pop-up menu which appears
upon right mouse button click (the other mouse events
are described in the
Mouse
events for display window section). The pop-up
menu together with its five cascades look like:
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Popup menu
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Palette cascade
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File cascade
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View cascade
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Display cascade
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Modify cascade
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Rotation: press-and-hold left
mouse button and move the pointer
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Zoom (+): press-and-hold Shift +
Left mouse button and move the pointer up
-
Zoom (-): press-and-hold Shift +
Left mouse button and move the pointer down
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Pop-up menu: press-and-hold the
right mouse button
![[Figure]](img/xcrysden-picture-small-new.jpg)