Solution LAB2 guanine 2 - Revision history

Daniele Varsano at 20:26, 18 March 2021

2021-03-18T20:26:50Z

← Older revision		Revision as of 20:26, 18 March 2021
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	* Back to the previous page: [[Electronic properties of isolated molecules#~~Exercise2~~]]		* Back to the previous page: [[Electronic properties of isolated molecules#Exercise 2]]

	==Step 1==		==Step 1==

2021-03-18T17:21:41Z

Step 4

← Older revision		Revision as of 17:21, 18 March 2021
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	*Repeat the calculations done before for different values of the vacuum and analyse again the HOMO level.		*Repeat the calculations done before for different values of the vacuum and analyse again the HOMO level.
	*How does ~~it compare~~ with the experimental IP		*How does -HOMO compares with the experimental IP (8.0-8.3 eV)
			*Can you explain why the agreement is so poor?

2021-03-18T17:20:33Z

Step 4

← Older revision		Revision as of 17:20, 18 March 2021
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	*Repeat the calculations done before for different values of the vacuum and analyse again the HOMO level.		*Repeat the calculations done before for different values of the vacuum and analyse again the HOMO level.
			*How does it compare with the experimental IP

2021-03-18T17:19:40Z

Step 4

← Older revision		Revision as of 17:19, 18 March 2021
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	''The new function appearing in the average cluster potential energy, is the difference between the Fourier series and Fourier transform form of the long range part of the potential energy evaluated at the quantized g-vector and will be referred to as the screening function because it is constructed to ‘‘screen’’ the interaction of the system with an infinite array of periodic images.''		''The new function appearing in the average cluster potential energy, is the difference between the Fourier series and Fourier transform form of the long range part of the potential energy evaluated at the quantized g-vector and will be referred to as the screening function because it is constructed to ‘‘screen’’ the interaction of the system with an infinite array of periodic images.''

			*Repeat the calculations done before for different values of the vacuum and analyse again the HOMO level.

2021-03-18T17:18:53Z

Step 3

← Older revision		Revision as of 17:18, 18 March 2021
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	In order to understand the observed dependency we can plot the electrostatic potential of the system for the different volume considered. In order to plot the electrostatic potential let's use the post-processing tool of QE (pp.x) and then we plot the average potential along a direction (e.g. z direction).		In order to understand the observed dependency we can plot the electrostatic potential of the system for the different volume considered. In order to plot the electrostatic potential let's use the post-processing tool of QE (pp.x) and then we plot the average potential along a direction (e.g. z direction).

			[[File:average_v.png]]

	~~[[File:average_v~~.~~png]]~~		Now you can look again at the eigenvalues(HOMO)calculated in the previous step taking the vacuum potential as a zero.

	==Step 4==		==Step 4==

2021-03-18T17:10:31Z

Step 3

← Older revision		Revision as of 17:10, 18 March 2021
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	==Step 3==		==Step 3==
			In order to understand the observed dependency we can plot the electrostatic potential of the system for the different volume considered. In order to plot the electrostatic potential let's use the post-processing tool of QE (pp.x) and then we plot the average potential along a direction (e.g. z direction).

2021-03-18T17:08:43Z

Step 2

← Older revision		Revision as of 17:08, 18 March 2021
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	Repeat the same calculation of step 1 by changing the volume of your supercell (e.g celldm(1)=20,25,30). You can also use a script to automatise the runs.		Repeat the same calculation of step 1 by changing the volume of your supercell (e.g celldm(1)=20,25,30). You can also use a script to automatise the runs.

	Then collect the results of the energy level as a function of the volume.		Then collect the results of the energy level as a function of the volume. You can observe a strong dependency of the eigenvalues from the volume of the supercell.

	==Step 3==		==Step 3==

2021-03-18T15:37:08Z

Step 3

2021-03-18T15:35:30Z

Step 3

2021-03-18T15:33:14Z

Step 3