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--- exercises:2016_uzh_cmest:basic_electronic_structure [2016/09/29 09:16] – [2. Step] tmueller
+++ exercises:2016_uzh_cmest:basic_electronic_structure [2020/08/21 10:15] (current) – external edit 127.0.0.1
@@ Line 5: / Line 5: @@
 ===== 1. Step: Run the calculation =====
-Run a CP2K calculation with the following (commented) input file:
+Create a new directory for this exercise and run a CP2K calculation with the following (commented) input file:
 <code - ethene.inp >
@@ Line 131: / Line 131: @@
 ===== 3. Step =====
-Now look at the *.cube files.
+Each cube-file contains the electronic density of one MO mapped onto a regular 3D-grid. Not all MOs were written to a cube-file, this is controlled by the ''PRINT_MO'' section. Their filenames tell you to which MO a cube-file belongs. For example ''ethene-WFN_00005_1-1_0.cube'' contains the 5th orbital.
-Each cube-file contains the electronic density of one MO mapped onto a regular 3D-grid. Not all MOs were written to a cube-file, this is controlled by the PRINT_MO section. Their filenames tell you to which MO a cube-file belongs. For example ''ethene-WFN_00005_1-1_0.cube'' contains the 5th orbital.
 Use VMD to visualize the cube-files:
   - To run: ''$ vmd ethene-WFN_00008_1-1_0.cube''
-  - To visualize the molecule (sometimes it's not visible by default):\\    **Graphics > Representations > Draw style > Drawing Method=CPK**
+  - To visualize the molecule (sometimes it's not visible by default):\\ go to **Graphics > Representations > Draw style** and set **Drawing Method** to **CPK**
   - Add a second representation by clicking on **Create Rep**
   - In this second representation set **Drawing Method=Isosurfaces** and **Draw=Wireframe**
@@ Line 152: / Line 150: @@
   - Compare the new input file with the one from the [[first_simulation_run|previous exercise]]: which keywords changed? which section is missing, respectively new? Lookup the description of the changed keywords and sections in the [[https://manual.cp2k.org/|CP2K Manual]]
-  - Quickly sketch the energy distribution of the MOs.
+  - From the output: What are the energies of the Highest Occupied MO (**HOMO**), Lowest Unoccupied MO (**LUMO**), and the band-gap (in electronvolt)?
-  - What's the energy of the HOMO, LUMO, and the band-gap?
+  - Use VMD to identify the shape of the $\pi$ and $\pi^*$ orbitals (submit images like the one from above)
-  - Use VMD to identify the shape and energy of the $\pi$ and $\pi^*$ orbitals.
+  - Repeat the calculation for Propene and find again the **HOMO**, **LUMO** and band-gap energies.
+<note tip>
+  - The eigenvalues are given in Hartree (//Eh//) while the band-gap is stated directly in electronvolt
+  - Lookup the molecular orbital diagram of Ethen to identify which MOs and therefore which cube files you need to open.
+  - Use the [[http://cccbdb.nist.gov/|Computational Chemistry Comparison and Benchmark DataBase]] to lookup the calculated geometry for Propene (CH2CHCH3), use the geometry made using a Hartree-Fock calculation and the ''6-311+G(3df,2pd)'' basis set.
+</note>