Electron Phonon Coupling - Revision history

Attacc: /* Double-grid method for the electron-phonon coupling (only in Yambo 5.x) */

2023-11-30T09:34:38Z

Double-grid method for the electron-phonon coupling (only in Yambo 5.x)

← Older revision		Revision as of 09:34, 30 November 2023
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	[[File:Formula dbgrid.png\|center\|Yambo tutorial image\| 500px]]		[[File:Formula dbgrid.png\|center\|Yambo tutorial image\| 500px]]

	In order to exploit the double-grid tool we need the phonon energies calculated on a fine grid. If you just want to test the functionality of Yambo you can download here some files with the phononic frequencies already calculated on different silicon grids: [https://www.yambo-code.org/educational/tutorials/files/si_freqs_files.tgz si_freqs_files.tgz] <br>		In order to exploit the double-grid tool we need the phonon energies calculated on a fine grid.
	~~Otherwise you~~ generate them by following the instructions below.		<!--If you just want to test the functionality of Yambo you can download here some files with the phononic frequencies already calculated on different silicon grids: [https://www.yambo-code.org/educational/tutorials/files/si_freqs_files.tgz si_freqs_files.tgz] <br> !-->
			You generate them by following the instructions below.

	'''<span style="color:red">Concerning the school, we suggest to use the precomputed frequencies provided above.</span>'''		'''<span style="color:red">Concerning the school, we suggest to use the precomputed frequencies provided above.</span>'''

Attacc: /* Phonons */

2023-11-30T09:25:15Z

Phonons

← Older revision		Revision as of 09:25, 30 November 2023
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	0.500000000 0.000000000 0.000000000 1		0.500000000 0.000000000 0.000000000 1
	0.500000000 -0.250000000 0.000000000 1		0.500000000 -0.250000000 0.000000000 1

			Notice that in the tgz file included in this page all input files are already prepared.

	===DVSCF===		===DVSCF===

Attacc: /* Q-points list */

2023-11-30T09:12:19Z

Q-points list

← Older revision		Revision as of 09:12, 30 November 2023
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	1. Read the q-points list. In the '''nscf''' folder, enter in the ${PREFIX}.save then run ''p2y'' to read the wave-functions.		1. Read the q-points list. In the '''nscf''' folder, enter in the ${PREFIX}.save then run ''p2y'' to read the wave-functions.

	2. Generate the setup file with the command ''yambo_ph -i ~~-V all~~'' and ~~uncomment the flag ''<span style="color:green">BSEscatt</span>'' then~~ run the setup.		2. Generate the setup file with the command ''yambo_ph -i'' and run the setup.
	setup # [R] Initialization		setup # [R] Initialization
	~~infver # [R] Input file variables verbosity~~
	~~K_grids= "X B S" # [KPT] Select the grids (X=response, S=sigma, C=collisions, B=bse) [default X S C B]~~
	~~BSEscatt # [KPT] Compute extended k/q scatering~~

	3. Generate the input file to read the electron-phonon matrix elements with the command ''ypp_ph -k q'':		3. Generate the input file to read the electron-phonon matrix elements with the command ''ypp_ph -k q'':

Attacc: /* SCF */

2023-11-30T09:02:35Z

SCF

← Older revision		Revision as of 09:02, 30 November 2023
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	......		......
	ibrav= 0,		ibrav= 0,
	celldm(1) =5.~~09150~~		celldm(1) =5.132
	.....		.....
	/		/

Attacc: /* Electron-phonon matrix elements */

2023-11-30T09:02:17Z

Electron-phonon matrix elements

← Older revision		Revision as of 09:02, 30 November 2023
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	In this tutorial we will show how to calculate electron-phonon induced corrections to the bands and optical properties for bulk silicon.		In this tutorial we will show how to calculate electron-phonon induced corrections to the bands and optical properties for bulk silicon.
	All input file are availabe in the following tgz file: [~~https~~://www.~~yambo-code~~.~~org~~/~~educational/tutorials/files~~/si.epc.tgz si.epc.tgz]		All input file are availabe in the following tgz file: [http://www.attaccalite.com/tutorials_yambo/si.epc.tgz si.epc.tgz]

	===SCF===		===SCF===

Attacc: /* Electron-phonon matrix elements */

2023-11-30T08:59:58Z

Electron-phonon matrix elements

← Older revision		Revision as of 08:59, 30 November 2023
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	== Electron-phonon matrix elements ==		== Electron-phonon matrix elements ==
	If you just want to see how Yambo works and leave the database generation for later, or use YamboPy to generate them, <br>		If you just want to see how Yambo works and leave the database generation for later, or use YamboPy to generate them, <br>
	you can skip this section and download ready-made databases: [~~https~~://www.~~yambo-code~~.~~org~~/~~educational~~/~~tutorials/files/si.epc~~.tgz Si_elph_dbs.tgz]		you can skip this section and download ready-made databases: [http://www.attaccalite.com/tutorials_yambo/Si_elph_dbs.tgz Si_elph_dbs.tgz]

Attacc: /* Electron-phonon matrix elements */

2023-11-30T08:59:11Z

Electron-phonon matrix elements

← Older revision		Revision as of 08:59, 30 November 2023
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	== Electron-phonon matrix elements ==		== Electron-phonon matrix elements ==
	If you just want to see how Yambo works and leave the database generation for later, or use YamboPy to generate them, <br>		If you just want to see how Yambo works and leave the database generation for later, or use YamboPy to generate them, <br>
	you can skip this section and download ready-made databases: [https://www.yambo-code.org/educational/tutorials/files/~~Si_elph_dbs~~.tgz Si_elph_dbs.tgz]		you can skip this section and download ready-made databases: [https://www.yambo-code.org/educational/tutorials/files/si.epc.tgz Si_elph_dbs.tgz]

Attacc: /* Quasi-particle band structure */

2023-11-30T08:49:35Z

Quasi-particle band structure

← Older revision		Revision as of 08:49, 30 November 2023
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	[https://arxiv.org/abs/1505.07738 Phys. Rev. B 92, 085137 (2015)] </ref>.		[https://arxiv.org/abs/1505.07738 Phys. Rev. B 92, 085137 (2015)] </ref>.
	This parameter will be used in the next tutorial on [https://www.yambo-code.org/wiki/index.php?title=Optical_properties_at_finite_temperature optical properties at finite temperature].		This parameter will be used in the next tutorial on [https://www.yambo-code.org/wiki/index.php?title=Optical_properties_at_finite_temperature optical properties at finite temperature].
	<br><span style="color:red"><b>WARNING:</b></span> Yambo average the electron-phonon correction on the degenerate states, please <b>include all degenerate states in your calculations</b>. For example in the silicon case you need correction from the 2nd band to the 8th band.		<br><br><span style="color:red"><b>WARNING:</b></span> Yambo average the electron-phonon correction on the degenerate states, please <b>include all degenerate states in your calculations</b>. For example in the silicon case you need correction from the 2nd band to the 8th band.

	== Convergence ==		== Convergence ==

Attacc: /* Electron-phonon matrix elements */

2023-11-30T08:48:03Z

Electron-phonon matrix elements

← Older revision		Revision as of 08:48, 30 November 2023
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	In this tutorial we will show how to calculate electron-phonon induced corrections to the bands and optical properties for bulk silicon.		In this tutorial we will show how to calculate electron-phonon induced corrections to the bands and optical properties for bulk silicon.
	~~<!--~~All input file are availabe in the following tgz file: [https://www.yambo-code.org/educational/tutorials/files/si.epc.tgz si.epc.tgz]~~-->~~		All input file are availabe in the following tgz file: [https://www.yambo-code.org/educational/tutorials/files/si.epc.tgz si.epc.tgz]

	===SCF===		===SCF===

Attacc: /* Electron-phonon matrix elements */

2023-11-30T08:46:10Z

Electron-phonon matrix elements

← Older revision		Revision as of 08:46, 30 November 2023
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	== Electron-phonon matrix elements ==		== Electron-phonon matrix elements ==
	If you just want to see how Yambo works and leave the database generation for later, or use YamboPy to generate them, you can skip this section and download ready-made databases ~~following the instructions of the~~ [~~[Tutorials#Tutorial_files\|Files Download section]~~]		If you just want to see how Yambo works and leave the database generation for later, or use YamboPy to generate them, <br>
			you can skip this section and download ready-made databases: [https://www.yambo-code.org/educational/tutorials/files/Si_elph_dbs.tgz Si_elph_dbs.tgz]


	Otherwise, in the cloud you need to load the quantum-espresso module:		Otherwise, in the cloud you need to load the quantum-espresso module: