Solution LAB2 guanine 3 - Revision history

Andrea Ferretti at 10:36, 26 March 2021

2021-03-26T10:36:38Z

← Older revision		Revision as of 10:36, 26 March 2021
Line 11:		Line 11:

	Using ecutwfc=50 Ry and 35 au of cell size,		Using ecutwfc=50 Ry and 35 au of cell size,
	E_tot(N) =		E_tot(N) = -193.48101821 Ry
	E_tot(N-1) = -192.89782124 Ry		E_tot(N-1) = -192.89782124 Ry

	giving		giving
			IP = E_tot(N-1) - E_tot(N)
			= 0.58319697 Ry
			= 7.934861 eV

			now much closer to the experimental value of 8.0-8.3 eV.

	Interestingly, one can run the same set of calculations also using different functionals,		Interestingly, one can run the same set of calculations also using different functionals,

Andrea Ferretti at 10:33, 26 March 2021

2021-03-26T10:33:38Z

← Older revision		Revision as of 10:33, 26 March 2021
Line 9:		Line 9:
	Also, the following option needs to be used for charged systems :		Also, the following option needs to be used for charged systems :
	assume_isolated="mt"		assume_isolated="mt"

			Using ecutwfc=50 Ry and 35 au of cell size,
			E_tot(N) =
			E_tot(N-1) = -192.89782124 Ry

			giving

			Interestingly, one can run the same set of calculations also using different functionals,
			including GGAs (PBE), meta-GGAs (eg TPSS or SCAN), hybrids (PBE0), or HF itself.

			In order to do this, you can force e.g. the functional from input, by using:

			&SYSTEM
			[...]
			input_dft="PBE0"
			/

			How do -eps_HOMO and delta-scf values compare ?

Andrea Ferretti at 09:52, 26 March 2021

2021-03-26T09:52:37Z

← Older revision		Revision as of 09:52, 26 March 2021
Line 3:		Line 3:
	For calculation of E(N-1) we need to set the following flags in the &SYSTEM namelist:		For calculation of E(N-1) we need to set the following flags in the &SYSTEM namelist:

	nspin=2 ! Note, now we have unpaired electrons:		nspin=2 ! Note, now we have unpaired electrons:
	tot_charge=+1 ! charged system		tot_charge=+1 ! charged system
	tot_magnetization=1 ! we need to set a total magnetisation		tot_magnetization=1 ! we need to set a total magnetisation

	Also, the following option needs to be used for charged systems :		Also, the following option needs to be used for charged systems :
	assume_isolated="mt"		assume_isolated="mt"

Andrea Ferretti at 09:52, 26 March 2021

2021-03-26T09:52:23Z

← Older revision		Revision as of 09:52, 26 March 2021
Line 1:		Line 1:
	* Back to the previous page: [[Electronic properties of isolated molecules#Exercise 3]]		* Back to the previous page: [[Electronic properties of isolated molecules#Exercise 3]]

	For calculation of E(N-1):		For calculation of E(N-1) we need to set the following flags in the &SYSTEM namelist:
	tot_charge=+1 !charged system
	~~consider~~ to ~~use~~ the option:		nspin=2 ! Note, now we have unpaired electrons:
			tot_charge=+1 ! charged system
			tot_magnetization=1 ! we need to set a total magnetisation

			Also, the following option needs to be used for charged systems :
	assume_isolated="mt"		assume_isolated="mt"
	~~Note, now we have unpaired electrons:~~
	~~nspin=2~~
	~~we need to set a total magnetisation:~~
	~~tot_magnetization=1~~

Daniele Varsano at 20:27, 18 March 2021

2021-03-18T20:27:03Z

← Older revision		Revision as of 20:27, 18 March 2021
Line 1:		Line 1:
	* Back to the previous page: [[Electronic properties of isolated molecules#~~Exercise3~~]]		* Back to the previous page: [[Electronic properties of isolated molecules#Exercise 3]]

	For calculation of E(N-1):		For calculation of E(N-1):

Daniele Varsano at 20:23, 18 March 2021

2021-03-18T20:23:45Z

← Older revision		Revision as of 20:23, 18 March 2021
Line 5:		Line 5:
	consider to use the option:		consider to use the option:
	assume_isolated="mt"		assume_isolated="mt"
			Note, now we have unpaired electrons:
			nspin=2
	~~nspin~~		we need to set a total magnetisation:
	tot_magnetization		tot_magnetization=1

Daniele Varsano at 20:21, 18 March 2021

2021-03-18T20:21:24Z

← Older revision		Revision as of 20:21, 18 March 2021
Line 1:		Line 1:
	* Back to the previous page: [[Electronic properties of isolated molecules#Exercise3]]		* Back to the previous page: [[Electronic properties of isolated molecules#Exercise3]]

	~~When dealing with cation pay attention~~ to		For calculation of E(N-1):
	~~tot_charge~~		tot_charge=+1 !charged system
			consider to use the option:
			assume_isolated="mt"


	nspin		nspin
	tot_magnetization		tot_magnetization

Daniele Varsano: Created page with "* Back to the previous page: Electronic properties of isolated molecules#Exercise3 When dealing with cation pay attention to tot_charge nspin tot_magnetization"

2021-03-18T20:18:36Z

Created page with "* Back to the previous page: Electronic properties of isolated molecules#Exercise3 When dealing with cation pay attention to tot_charge nspin tot_magnetization"

New page

* Back to the previous page: [[Electronic properties of isolated molecules#Exercise3]]

When dealing with cation pay attention to
tot_charge
nspin
tot_magnetization