Calculating the electric field gradient - Revision history

Csheldon: /* Related tags and articles */

2025-05-12T11:39:31Z

Csheldon at 11:37, 12 May 2025

2025-05-12T11:37:06Z

← Older revision		Revision as of 11:37, 12 May 2025
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	done		done
	</pre>		</pre>

			== Related tags and articles ==
			{{TAG\|LEFG}}
			{{TAG\|QUAD_EFG}}

	==References==		==References==

	[[Category:Howto]][[Category:NMR]]		[[Category:Howto]][[Category:NMR]]

Csheldon: /* PAW pseudopotentials */

2025-03-26T08:13:24Z

PAW pseudopotentials

← Older revision		Revision as of 08:13, 26 March 2025
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	===PAW pseudopotentials===		===PAW pseudopotentials===
	The standard [[:Category:Pseudopotentials\|PAW pseudopotentials]] {{FILE\|POTCAR}} used are sufficient for calculating the electric field gradient. Using [[Available pseudopotentials\|GW pseudopotentials]] can significantly improve results. Semi-core electrons can be important, so {{TAG\|~~POSCAR~~}} files with ''_pv'' or ''_sv'' can improve the results, as will the explicit inclusion of augmentation channels with <math>d</math>-projectors.		The standard [[:Category:Pseudopotentials\|PAW pseudopotentials]] {{FILE\|POTCAR}} used are sufficient for calculating the electric field gradient. Using [[Available pseudopotentials\|GW pseudopotentials]] can significantly improve results. Semi-core electrons can be important, so {{TAG\|POTCAR}} files with ''_pv'' or ''_sv'' can improve the results, as will the explicit inclusion of augmentation channels with <math>d</math>-projectors.

	===Additional tags===		===Additional tags===

Csheldon at 12:25, 25 March 2025

2025-03-25T12:25:34Z

← Older revision		Revision as of 12:25, 25 March 2025
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	Nuclei with a spin > ± ½ are called quadrupolar nuclei. They have a non-spherical shape and therefore a non-zero ~~[[Electric Field Gradient\|~~electric field gradient]] (EFG) at the nucleus. The EFG is calculated using {{TAG\|LEFG}} {{Cite\|petrilli:prb:1998}}. By including the quadrupole moment of the isotopes, the quadrupole coupling constants ''C<sub>q</sub>'' can be calculated (multiple definitions exist in the literature, ensure that you are correctly comparing). These are measured using nuclear quadrupole resonance (NQR) spectroscopy, a type of zero- to ultralow-field (ZULF) NMR, NMR, and Mössbauer spectroscopy. The theory is covered in the [[:Category:NMR\|NMR category page]] and {{TAG\|LEFG}} page.		Nuclei with a spin > ± ½ are called quadrupolar nuclei. They have a non-spherical shape and therefore a non-zero electric field gradient (EFG) at the nucleus. The EFG is calculated using {{TAG\|LEFG}} {{Cite\|petrilli:prb:1998}}. By including the quadrupole moment of the isotopes, the quadrupole coupling constants ''C<sub>q</sub>'' can be calculated (multiple definitions exist in the literature, ensure that you are correctly comparing). These are measured using nuclear quadrupole resonance (NQR) spectroscopy, a type of zero- to ultralow-field (ZULF) NMR, NMR, and Mössbauer spectroscopy. The theory is covered in the [[:Category:NMR\|NMR category page]] and {{TAG\|LEFG}} page.

	==Step-by-step instructions==		==Step-by-step instructions==

Csheldon: /* References */

2025-03-19T09:44:39Z

References

← Older revision		Revision as of 09:44, 19 March 2025
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	==References==		==References==

	~~<!--~~ [[Category:Howto]][[Category:NMR]] ~~--!>~~		[[Category:Howto]][[Category:NMR]]

Csheldon: Csheldon moved page Construction:Calculating the electric field gradient to Calculating the electric field gradient

2025-03-10T09:30:51Z

Csheldon moved page Construction:Calculating the electric field gradient to Calculating the electric field gradient

← Older revision	Revision as of 09:30, 10 March 2025
(No difference)

Csheldon at 18:14, 7 March 2025

2025-03-07T18:14:25Z

← Older revision		Revision as of 18:14, 7 March 2025
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	Nuclei with a spin > ± ½ are called quadrupolar nuclei. They have a non-spherical shape and therefore a non-zero [[Electric Field Gradient\|electric field gradient]] (EFG) at the nucleus. The EFG is calculated using {{TAG\|LEFG}} {{Cite\|petrilli:prb:1998}}. By including the quadrupole moment of the isotopes, the quadrupole coupling constants ''C<sub>q</sub>'' can be calculated (multiple definitions exist in the literature, ensure that you are correctly comparing). These are measured using nuclear quadrupole resonance (NQR) spectroscopy, a type of zero- to ultralow-field (ZULF) NMR. The theory is covered in the [[:Category:NMR\|NMR category page]] and {{TAG\|LEFG}} page.		Nuclei with a spin > ± ½ are called quadrupolar nuclei. They have a non-spherical shape and therefore a non-zero [[Electric Field Gradient\|electric field gradient]] (EFG) at the nucleus. The EFG is calculated using {{TAG\|LEFG}} {{Cite\|petrilli:prb:1998}}. By including the quadrupole moment of the isotopes, the quadrupole coupling constants ''C<sub>q</sub>'' can be calculated (multiple definitions exist in the literature, ensure that you are correctly comparing). These are measured using nuclear quadrupole resonance (NQR) spectroscopy, a type of zero- to ultralow-field (ZULF) NMR, NMR, and Mössbauer spectroscopy. The theory is covered in the [[:Category:NMR\|NMR category page]] and {{TAG\|LEFG}} page.

	==Step-by-step instructions==		==Step-by-step instructions==

Csheldon: /* Energy cutoff tests */

2025-03-07T15:38:17Z

Energy cutoff tests

← Older revision		Revision as of 15:38, 7 March 2025
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	{{TAGBL\|QUAD_EFG}} = 0. -696. 20.44 0. 2.860 # Nuclear quadrupolar moments for Pb I N O D		{{TAGBL\|QUAD_EFG}} = 0. -696. 20.44 0. 2.860 # Nuclear quadrupolar moments for Pb I N O D

	Script to loop through {{TAG\|ENCUT}} from 400 eV to ~~600~~ eV:		Script to loop through {{TAG\|ENCUT}} from 400 eV to 800 eV:
	<pre>		<pre>
	for a in 400 500 600 700 800		for a in 400 500 600 700 800

Csheldon: /* Energy cutoff tests */

2025-03-07T15:32:49Z

Energy cutoff tests

← Older revision		Revision as of 15:32, 7 March 2025
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	==Energy cutoff tests==		==Energy cutoff tests==
	For converging the energy cutoff, start ~~with~~ the value of ENMAX given in the {{FILE\|POTCAR}} file and then increase incrementally in steps of 100 eV:		For converging the energy cutoff, start from at least the value of ENMAX given in the {{FILE\|POTCAR}} file and then increase incrementally in steps of 100 eV:

	Initial {{TAGBL\|INCAR}}:		Initial {{TAGBL\|INCAR}}:

Csheldon: /* Energetic break criterion tests */

2025-03-07T15:29:58Z

Energetic break criterion tests

← Older revision		Revision as of 15:29, 7 March 2025
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	{{TAGBL\|ENCUT}} = 400		{{TAGBL\|ENCUT}} = 400
	{{TAGBL\|ISMEAR}} = 0; {{TAGBL\|SIGMA}} = 0.01		{{TAGBL\|ISMEAR}} = 0; {{TAGBL\|SIGMA}} = 0.01
	{{TAGBL\|EDIFF}} = 1E-8		{{TAGBL\|EDIFF}} = 1E-4
	{{TAGBL\|PREC}} = Accurate		{{TAGBL\|PREC}} = Accurate
	{{TAGBL\|LASPH}} = .TRUE.		{{TAGBL\|LASPH}} = .TRUE.

← Older revision		Revision as of 11:39, 12 May 2025
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	== Related tags and articles ==		== Related tags and articles ==
	{{TAG\|LEFG}}		{{TAG\|LEFG}},
	{{TAG\|QUAD_EFG}}		{{TAG\|QUAD_EFG}}

← Older revision		Revision as of 15:29, 7 March 2025
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	{{TAGBL\|ENCUT}} = 400		{{TAGBL\|ENCUT}} = 400
	{{TAGBL\|ISMEAR}} = 0; {{TAGBL\|SIGMA}} = 0.01		{{TAGBL\|ISMEAR}} = 0; {{TAGBL\|SIGMA}} = 0.01
	{{TAGBL\|EDIFF}} = 1E-8		{{TAGBL\|EDIFF}} = 1E-4
	{{TAGBL\|PREC}} = Accurate		{{TAGBL\|PREC}} = Accurate
	{{TAGBL\|LASPH}} = .TRUE.		{{TAGBL\|LASPH}} = .TRUE.