[Pw_forum] SCF doesn't converge in charged supercell

[feng.zimin at ireq.ca]

Hi Franco,
 
If you are doing surface then you'd better do Gamma point only (non-shifted). Also if there are magnetizations at all, you must not specify tot_magnetization = 0 .
 
Try this first. If it doesn't work try using a smaller mix parameter.
 
fzm

________________________________

De : pw_forum-bounces at pwscf.org [mailto:pw_forum-bounces at pwscf.org] De la part de Franco Bonafé
Envoyé : 4 juin 2013 14:37
À : PWSCF Forum
Objet : Re: [Pw_forum] SCF doesn't converge in charged supercell


Hi Feng, 
It is non magnetic. I am using spin polarization because I am expecting localized states in the surface. The electronic structure of the the first scf calculation doesn't converge and by grep of total energy I don't really see any sign of convergence. Can it be just an issue with the k-points or is there anything else that is precluding convergence?
Thanks.
Franco.



2013/6/4 <feng.zimin at ireq.ca>


	
	Hi Franco,
	A few questions. Is it an antiferro system? Why do you think you need spin polarization for relaxation? Why do you shift the K points?  Is it electronic structure or the atomic positions that are not converged? Are there any signs of convergence from the output?
	fzm

________________________________

	De : pw_forum-bounces at pwscf.org [mailto:pw_forum-bounces at pwscf.org] De la part de Franco Bonafé
	Envoyé : 4 juin 2013 13:45
	À : PWSCF Forum
	Objet : [Pw_forum] SCF doesn't converge in charged supercell
	
	
	Hi to all,
	I am trying to perform a relaxation in a charged cell and it reaches the maximun number of steps and doesn't achieve convergence.
	What am I doing wrong?
	Thanks in advance.
	Franco.

	Input script:

	 &CONTROL
	                 calculation = 'relax' ,
	                restart_mode = 'from_scratch' ,
	                      outdir = '/home/tmp' ,
	                  pseudo_dir = '/home/pseudo/' ,
	                      prefix = 'anath2oLi ,
	               etot_conv_thr = 1.0D-3 ,
	               forc_conv_thr = 1.0D-2 ,
	 /
	 &SYSTEM
	                       ibrav = 0,
	                   celldm(1) = 19.3262367 ,
	                         nat = 73 ,
	                        ntyp = 4 ,
	                     ecutwfc = 30. ,
	                     ecutrho = 300. ,
	                  tot_charge = 1.000000,
	                 occupations = 'smearing' ,
	                     degauss = 0.03 ,
	                    smearing = 'methfessel-paxton' ,
	                       nspin = 2 ,
	           tot_magnetization = 0,
	 /
	 &ELECTRONS
	                    conv_thr = 1.0d-6 ,
	                 mixing_mode = 'local-TF' ,
	                 mixing_beta = 0.7 ,
	             diagonalization = 'david' ,
	 /
	 &IONS
	                ion_dynamics = 'bfgs' ,
	 /
	CELL_PARAMETERS alat 
	     1.010387266    0.000000000    0.000000000 
	     0.000000000    0.709834502    0.000000000 
	     0.000000000    0.000000000    2.151168486 
	ATOMIC_SPECIES
	    O   15.99940  O.pbe-van_ak.UPF 
	   Ti   47.86700  Ti.pbe-sp-van_ak.UPF 
	    H    1.00794  H.pbe-van_ak.UPF 
	   Li    6.94100  Li.pbe-s-van_ak.UPF 
	ATOMIC_POSITIONS angstrom 
	...
	K_POINTS automatic 
	  1 1 1   1 1 1 


	-- 
	
	
	Franco P. Bonafé
	Chemistry Student
	Undergrad Research Assistant
	Department of Math & Physics
	National University of Córdoba
	Argentina
	
	
	+57 9 0351 15 5472791
	fbonafe at fcq.unc.edu.ar

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-- 

Franco P. Bonafé
Chemistry Student
Undergrad Research Assistant
Department of Math & Physics
National University of Córdoba
Argentina


+57 9 0351 15 5472791
fbonafe at fcq.unc.edu.ar
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