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--- exercises:2018_ethz_mmm:bands_i_2018 [2018/04/25 09:34] – dpasserone
+++ exercises:2018_ethz_mmm:bands_i_2018 [2020/08/21 10:15] (current) – external edit 127.0.0.1
@@ Line 6: / Line 6: @@
 of HfO2 to form silicates played a key role in the industrial transition.
+<note importat>
+please download
+ **hfo2.py, PhysRevB...pdf, bands_si.py, bands_cu.py** from [[https://polybox.ethz.ch/index.php/s/CH5VdcI40YdELez|this link]]
+</note>
-<note important>
 ====Task1====
-Construct the primitive cell of the monoclinic phase of HfO2, using ASE and teh information contained in the manuscript
+Construct the primitive cell of the monoclinic phase of HfO2, using ASE and teh information contained in the HfO2 manuscript
-<note warning>Follow the instructions contained in the ASE webpage dedicated to spacegroups
+<note tip>
+Follow the instructions contained in the ASE webpage dedicated to spacegroups
 [[https://wiki.fysik.dtu.dk/ase/ase/spacegroup/spacegroup.html]]
-and find in this article (a pdf copy is included in the tar file of the exercise)
+and find in this article (a pdf copy is included in dropbox)
 [[https://journals.aps.org/prb/abstract/10.1103/PhysRevB.65.233106]]
@@ Line 26: / Line 30: @@
 (replace "...")
+**(comment the line "hfo2.write("hfo2.png")")**
 Execution of the python script
@@ Line 33: / Line 39: @@
 will open the ASE visualizer showing you the structure,
-will produce the file hfo2.xyz, hfo2.png and hfo2.pov
+will produce the file hfo2.xyz, (hfo2.png)
-to create a "nice" image of the primitive cell you can render the output file hfo2.pov with the command
-<code>
-povray +W320 +H320 -I./hfo2.pov -Ohfo2 +P +X +A +FJ +C
-</code>
-or executing the script
-<code>
-./povray.sc
-</code>
-(that will take care of removing files hfo2.jpg and hfo2.inc)
 </note>
-<note warning>
+<note important>
 -how many atoms are contained in the unit cell?
@@ Line 54: / Line 50: @@
 ====Task2====
 Have a look at the atomic coordinates, for example in the file hfo2.xyz (where you also find the cell vectors in cartesian coordinates) and
-<note warning>
+<note important>
 try to reproduce them (just the 4 Hf atoms), starting from the
 coordinates that you find in the article and applying the symmetry operations of the space group:
@@ Line 65: / Line 61: @@
 )x,-y+1/2,z+1/2
+<note tip>
 **DO NOT FORGET Periodic Boundary Conditions!!** but it's simple: x,y,z are given in crystal coordinates so, if for example x=0.276
 for "-x" you can use -x+1 = 0.724
-</note>
-<note important>
 usually the coordinates are provided in crystal coordinates so
-if a1=(a1x,a1y,a1z),a2=(a2x,a2y,a2z),a3=(a3x,a3y,a3z) are the three basis vectors of the crystalin cartesian coordinates
+if a1=(a1x,a1y,a1z),a2=(a2x,a2y,a2z),a3=(a3x,a3y,a3z) are the three basis vectors of the crystal in cartesian coordinates
-and (x1,y1,z1) will be the crystal coordinates of atom 1, the cartessian coordinates of atom 1 will be:
+and (x1,y1,z1)  the crystal coordinates of atom 1, the cartesian coordinates of atom 1 will be:
 x1*a1 + x2*a2 + x3*a3
 </note>
+</note>
+<note important>obtain teh HfO2 structure from [[https://materialsproject.org/]]</note>
 ====Task 3====
 Check the lecture notes for the free electron model and:
-<note warning>Compute the Fermi energy (in eV) and the Fermi wavevector (in cm-1) for Cu,Au,Ag </note>
+<note important>Compute the Fermi energy (in eV) and the Fermi wavevector (in cm-1) for Cu,Au,Ag </note>
@@ Line 88: / Line 84: @@
 [[https://wiki.fysik.dtu.dk/ase/ase/dft/kpoints.html]]
-<note warning>
+<note important>
 Compute the free electron bandstructure of Si and Cu
-(Have a look at the scripts included in the exercise directory)
 Write the CARTESIAN COORDINATES of the Gamma, X, W points of FCC
+<note tip>
+Have a look at the scripts included in the exercise directory
+</note>
+<note warning>How does the Fermi energy that you computed for Cu compares with the one plotted in the bands?</note>
 </note>