exercises:2017_uzh_cmest:pdos
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exercises:2017_uzh_cmest:pdos [2017/10/17 15:55] – jglan | exercises:2017_uzh_cmest:pdos [2020/08/21 10:15] (current) – external edit 127.0.0.1 | ||
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+ | ======= Projected density of states and Band structure for WO$_3$ ======= | ||
In this exercise, you will carry out Density Of States(DOS) and band structure calculation using K-point sampling for Cubic lattice WO$_3$. The reference DOS and band structure you can find in [[http:// | In this exercise, you will carry out Density Of States(DOS) and band structure calculation using K-point sampling for Cubic lattice WO$_3$. The reference DOS and band structure you can find in [[http:// | ||
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{{: | {{: | ||
- | ======= Projected density of states for WO$_3$ ======= | + | ====== |
- | In the following exercise we are going to look at the density of states of WO$_3$: | + | |
+ | In the following exercise we are going to look at the density of states of < | ||
Similar to the previous exercise we write the coordinates in term of the unit cell: | Similar to the previous exercise we write the coordinates in term of the unit cell: | ||
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< | < | ||
- | Alternatively, | + | Alternatively, |
<note important> | <note important> | ||
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While some of the new options to help with convergence are of numerical nature, [[howto: | While some of the new options to help with convergence are of numerical nature, [[howto: | ||
+ | |||
+ | < | ||
* Repeat the above calculation for the different multiple cells 3x3x3, 4x4x4 | * Repeat the above calculation for the different multiple cells 3x3x3, 4x4x4 | ||
- | * Do you see why it is necessary to do the unit cell replication? | + | |
+ | | ||
+ | * What is the value of WO$_3$ band gap? Compare the plots for 3x3x3 and 4x4x4. | ||
* .. which state ($s$, $p_x$, ..) is mainly responsible for that? | * .. which state ($s$, $p_x$, ..) is mainly responsible for that? | ||
* Change the $\sigma$ value in convolution program, and determine a reasonable value for the PDOS plot | * Change the $\sigma$ value in convolution program, and determine a reasonable value for the PDOS plot | ||
+ | </ | ||
+ | ====== Getting the band structure of WO$_3$ Lattice ====== | ||
- | ======= Getting the band structure of WO$_3$ Lattice ======= | + | To get the band structure for < |
- | + | ||
- | To get the band structure for WO3, only a few changes are required compared to the previous example for [[PDOS|calculating the PDOS]]: | + | |
<code - WO3-bs.inp> | <code - WO3-bs.inp> | ||
&GLOBAL | &GLOBAL | ||
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& | & | ||
| | ||
- | | ||
| | ||
- | | + | SYMMETRY .FALSE. |
- | | + | FULL_GRID .FALSE. |
+ | | ||
&END KPOINTS | &END KPOINTS | ||
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* The keyword '' | * The keyword '' | ||
* The '' | * The '' | ||
+ | |||
+ | <note tip>You are encouraged to use [[ http:// | ||
+ | <code - WO3-cubic.xyz> | ||
+ | 4 | ||
+ | WO3; a=3.810000 | ||
+ | | ||
+ | | ||
+ | | ||
+ | | ||
+ | </ | ||
+ | </ | ||
+ | |||
Now, when you run this input file you will get in addition the the output file, a file named '' | Now, when you run this input file you will get in addition the the output file, a file named '' | ||
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For each set there is a block named '' | For each set there is a block named '' | ||
+ | < | ||
Your tasks: | Your tasks: | ||
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* Compare your plot with plots from literature. What is different? | * Compare your plot with plots from literature. What is different? | ||
* How many orbital energies do you get and why? Try to change the input to get more unoccupied orbitals. | * How many orbital energies do you get and why? Try to change the input to get more unoccupied orbitals. | ||
+ | </ | ||
+ | |||
To convert the band structure file to a file which can be plotted directly, you can use the script '' | To convert the band structure file to a file which can be plotted directly, you can use the script '' | ||
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</ | </ | ||
- |
exercises/2017_uzh_cmest/pdos.1508255742.txt.gz · Last modified: 2020/08/21 10:15 (external edit)