[Pw_forum] charging a metal ion in front of insulating plane

[degironc]

I guess you are dealing with a rare earth or lanthanoid element. I would play with gga+u at the very least.
This c/should fix the nonlinearity in the charge transfer to/from the adatom.
No guarantee that you get what you want but more imlortantly what the system really wants.
It depends on the surface workfunction in comparison to the element electron affinity.
Good luck,
StefanoSent from my Samsung Galaxy smartphone.
-------- Original message --------From: Christoph Wolf <wolf.christoph at qns.science> Date: 08/12/2017  05:39  (GMT+01:00) To: pw_forum at pwscf.org Subject: [Pw_forum] charging a metal ion in front of insulating plane 
Dear all,

I am struggling to charge a metal ion in front of an insulating MgO plane; I build an inversion symmetric 5-layer MgO plane and place an ion 2 A away from it. The relaxation of the system gives ~1.7 A for the neutral and 2.1 A for the (tot_charge=-1) charged ion. When looking at the projwfc.x output the "charge state" of the ion, despite being far away from the surface, is only marginally charged:
1) neutral case pw.x: number of electrons       =      1456.00pw.x: total magnetization       =     4.00 Bohr mag/cellpw.x: atom:  181    charge:   13.7470    magn:    3.2676projwfc.x: Atom # 181: total charge =  15.4842, s =  3.0695, p =  5.9947, d =  6.4201, 

2) negatively chargednumber of electrons       =      1457.00
pw.x: total magnetization       =     1.02 Bohr mag/cellpw.x: atom:  181    charge:   13.8845    magn:    0.9465total charge =  15.6842, s =  2.9801, p =  5.9931, d =  6.7109, 

-- 
Postdoctoral Researcher
Center for Quantum Nanoscience, Institute for Basic Science
Ewha Womans University, Seoul, South Korea

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