The ABINIT Users Mailing List ( CLOSED )

[Bernard Amadon <bernard.amadon@cea.fr>]

Dear Qian,

(1) In PAW+U, dmatpuopt =2 is more general , using dmatpuopt=1  is only 
justified in some cases (see
http://www.abinit.org/Infos_v5.6/input_variables/varpaw.html#dmatpuopt).
Moreover, maybe you could start the convergency studies with the unit 
cell first.
In this new system density matrices would be probably simpler and 
convergence would be better.

(2) Have you tried to first compute the dos in LDA ? I think it is not a 
specific LDA+U problem
but you could first check it.

Best
Bernard


hyello25 Qgrui a écrit :
> Hi,Bernard Amadon
>
> Thanks for your kind reply and answers.
>
> (1) After your advices, I performed the PAW+U calculation again. The 
> input file is cited below:
> -------------------------------------------------------
>   ndtset  1
>   jdtset  1  
>
>   ecut   40                # I have not done detail ecut & pawecutdg 
> convergency calculation,         
>                                # just give large enough ecut and  
> pawecutdg  myself
>  pawecutdg   60
>
> #----- spin  -------#
> nsppol  2
> nspden  2
> nspinor 1
> spinat 
>         0  0 -3
>         0  0 -3
>  
>         0  0  2
>         0  0  2
>
>         0  0  0
>         0  0  0
>         0  0  0
>         0  0  0
>         0  0  0
>         0  0  0
>           
> #-------- LDA+U
> usepawu     1
> lpawu   2  2  -1
> upawu   0.30   0.30   0.00
> jpawu   0.035  0.035  0.000
>
> dmatpuopt   1       # choose expression of the density matrix
> usedmatpu   60
> dmatpawu            # The initial density matrix
>      # Mn atom 1 (spin-up )
>      0.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
> #-----------------------------------------------------------------------#
>      # Mn atom 1 (spin-down )
>      1.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    1.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    1.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
> #-----------------------------------------------------------------------#
>      # Mn atom 2 (spin-up )
>      0.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
> #-----------------------------------------------------------------------#
>      # Mn atom 2 (spin-down )
>      1.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    1.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    1.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
> #-----------------------------------------------------------------------#
>      # Ni atom 1 (spin-up )
>      1.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    1.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    1.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    1.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    1.00000
> #-----------------------------------------------------------------------#
>      # Ni atom 1 (spin-down )
>      1.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    1.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    1.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
> #-----------------------------------------------------------------------#
>      # Ni atom 2 (spin-up )
>      1.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    1.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    1.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    1.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    1.00000
> #-----------------------------------------------------------------------#
>      # Ni atom 2 (spin-down )
>      1.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    1.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
>      0.00000    0.00000    0.00000    1.00000    0.00000
>      0.00000    0.00000    0.00000    0.00000    0.00000
> #-----------------------------------------------------------------------#
> #nband 65
> #Starting approximation for the unit cell
>   acell   3*9.99
>   rprim   0.511293 -0.295195  0.807118 
>           0.000000  0.590390  0.807118 
>          -0.511293 -0.295195  0.807118
> chkprim   0
> #Definition of the atom types and atoms
>  ntypat   3
>   znucl   25  28  8
>   natom   10
>   typat   1 1   2 2  6*3  #  2xMn  2xNi  6xO
>
> #Starting approximation for atomic positions in REDUCED coordinates
>    xred 
>            0.25    0.25    0.25  #  Mn
>            0.75    0.75    0.75  #  Mn
>            0.50    0.50    0.50  #  Ni
>            0.00    0.00    0.00  #  Ni
>            0.50    0.00    0.00  #  O
>            0.00    0.50    0.00  #  O
>            0.00    0.00    0.50  #  O
>            0.50    0.50    0.00  #  O
>            0.50    0.00    0.50  #  O
>            0.00    0.50    0.50  #  O
> #---------------------------------------
> #Definition of the k-point grid
> kptopt 1
> kptrlatt 6 0 0
>            0 6 0
>            0 0 6
> nsym 0
> optforces  2
> #-----------------------#
> prtdos     2
> #-----------------------#
> prtdos2    3
> natsph2    10
> ratsph2    2*1.92 2*1.92 6*1.0
> iatsph2    1 2 3 4 5 6 7 8 9 10
> prtdos2    3
>
> #pawprtdos2  3
> #-----------------------#
>
> #Definition of the self-consistency procedure
>   diemix 0.9
>   occopt 7
>   tsmear 5.0d-3
>
>  npulayit 5
>    nline  15
>    ixc    11
>    iscf   17             
>   nstep   500            
>  tolvrs   1.0d-10
> ---------------------------------------------------------------
> And I am supposed to set the Ni(+2) a High-spin (t2g)6(eg2) and Mn(+4) 
> a High-spin (t2g)3 state, am I right? But it is still very hard to get 
> a convergency even more than 400scf steps.
>
> (2) I met another _huge_ problem when printing pDOS in PAW+U 
> calculation. As showed in the input file, I tried two different ways 
> to get pDOS in NiMnO3 systems, but both ways failed. After the scf 
> have done (of course not got convergency in NiMnO3) the program seems 
> to start calculating the pDOS. While at the same time the memory used 
> increases incredible(more than 2Gb per CPU abinip process). Then the 
> connection between nodes failed, as a error info mentioned. The same 
> situation (memory increased, while not much memory used) in simple NiO 
> system as well, but I succeeded to get the pDOS both ways. I donot 
> know why.
>
> The system info :  ABINT v5.6.3, x86_64_linux, intel ifort 9.1, 
> openmpi2, CentOS update4.
>
> Hope to give me some advices, thanks a lot.
>
> Bests,
> Qian
>
>
> -------------------------------------
> Qian Guangrui
> Graduated students
> Physics Department
> Nanjing University
> Nanjing 210093 China
> E-mail: hyello25@gmail.com <mailto:hyello25@gmail.com>