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xirainbow

木虫 (正式写手)

[资源] 【原创】LSDA for antiferromagnetic state

以下内容来自我的博客：
http://blog.sina.com.cn/s/blog_5f15ead20100drss.html

It is well known that the ground state of zigzag graphene ribbon is antiferromagnetic state. I fullfill the non-polarized and antiferromagnetic in one day, but the antiferromagnetic condition puzzled me for almost one month

   Two week ago, I finally get the antiferromagnetic state of zigzag graphene ribbon. The following is what I have learned from antiferromagnetic calculation.

   In the INPUT_PW document, it says that "starting spin polarization (values between -1 and 1)on atomic type 'i' in a spin-polarized calculation. Breaks the symmetry and provides a starting point for self-consistency. The default value is zero, BUT a value MUST be specified for AT LEAST one atomic type in spin polarized calculations. Note that if start from zero initial magnetization, you will get zero final magnetization in any case. If you desire to start from an antiferromagnetic state, you may need to define two different atomic species corresponding to sublattices of the same atomic type.(I was puzzled by this statement for a long time, but now I got it) If you fix the magnetization with "nelup/neldw" or with "multiplicity" or with "tot_magnetization", you should not specify starting_magnetization. If you are restarting from a previous run, or from an interrupted run, starting_magnetization is ignored."

###################################################
INPUT FILE OF GRAPHENE RIBBON 6
Input file:graphene.rx.in
&CONTROL
               calculation = 'relax' ,
            restart_mode = 'from_scratch' ,
                  outdir = '/home/raman/graphene/g55mag/' ,
               pseudo_dir = '/home/raman/accessory-soft/pseudo/' ,
            etot_conv_thr = 1.0e-4 ,
            forc_conv_thr = 1.0e-3 ,
                  tstress = .true. ,
                  tprnfor = .true. ,
/
&SYSTEM
                     ibrav = 8,
               celldm(1) = 4.67689278,
               celldm(2) = 8.623989813,
               celldm(3) = 4.048794087,
                     nat = 12,
                     ntyp = 2,// the largest ntype=10
                  ecutwfc = 60.D0 ,
                  ecutrho = 500.D0 ,
                     nosym = .false. ,
                     nbnd = 36,
                     nelec = 48,
               occupations = 'smearing' ,
                  degauss = 0.02 ,
                  smearing = 'gaussian' ,
                     nspin = 2 ,
starting_magnetization(1) = 1.0,
starting_magnetization(2) = -0.5,
/
&ELECTRONS
                  conv_thr = 1.D-6 ,
               mixing_mode = 'plain' ,
               mixing_beta = 0.7D0 ,
         diagonalization = 'david' ,
         diago_david_ndim = 8,
/
&IONS
            ion_dynamics = 'damp' ,
         pot_extrapolation = 'second_order' ,
         wfc_extrapolation = 'second_order' ,
/
ATOMIC_SPECIES
C1 12.00000  C.pbe-rrkjus.UPF
C2 12.00000  C.pbe-rrkjus.UPF
ATOMIC_POSITIONS crystal
C1    0.000000000 0.236465542 0.000000000
C2    0.500000000 0.265456486 0.000000000
C1    0.500000000 0.334092417 0.000000000
C2    0.000000000 0.366772814 0.000000000
C1    0.000000000 0.433673757 0.000000000
C2    0.500000000 0.466640035 0.000000000
C1    0.500000000 0.533360168 0.000000000
C2    0.000000000 0.566326232 0.000000000
C1    0.000000000 0.633227130 0.000000000
C2    0.500000000 0.665907475 0.000000000
C1    0.500000000 0.734543349 0.000000000
C2    0.000000000 0.763534596 0.000000000
K_POINTS automatic
  13 1 1 0 0 0

***************************************************************
Input file:graphene.scf.in
&CONTROL
               calculation = 'scf' ,
            restart_mode = 'from_scratch' ,
                  outdir = '' ,
               pseudo_dir = '' ,
            etot_conv_thr = 1.0e-4 ,
            forc_conv_thr = 1.0e-3 ,
                  tstress = .true. ,
                  tprnfor = .true. ,
/
&SYSTEM
                     ibrav = 8,
               celldm(1) = 4.67689278,
               celldm(2) = 8.623989813,
               celldm(3) = 4.048794087,
                     nat = 12,
                     ntyp = 2,
                  ecutwfc = 60.D0 ,
                  ecutrho = 500.D0 ,
                     nosym = .false. ,
                     nbnd = 36,
                     nelec = 48,
               tot_charge = 0.000000,
               occupations = 'smearing' ,
                  degauss = 0.02 ,
                  smearing = 'gaussian' ,
                     nspin = 2 ,
starting_magnetization(1) = 1.0,
starting_magnetization(2) = -0.5,
/


***************************************************************
Input file:graphene.band.in
&CONTROL
               calculation = 'nscf' ,
            restart_mode = 'from_scratch' ,
                  outdir = '/home/raman/graphene/g55mag/' ,
               pseudo_dir = '/home/raman/accessory-soft/pseudo/' ,
/
&SYSTEM
                     ibrav = 8,
               celldm(1) = 4.67689278,
               celldm(2) = 8.623989813,
               celldm(3) = 4.048794087,
                     nat = 12,
                     ntyp = 2,
                  ecutwfc = 60.D0 ,
                  ecutrho = 500.D0 ,
                     nosym = .false. ,
                     nbnd = 36,
                     nelec = 48,
               tot_charge = 0.000000,
               occupations = 'smearing' ,
                  degauss = 0.02 ,
                  smearing = 'gaussian' ,
                     nspin = 2 ,
starting_magnetization(1) = 1.0,
starting_magnetization(2) = -0.5,
/
&ELECTRONS
.................
/
ATOMIC_SPECIES
.................
ATOMIC_POSITIONS crystal
...............
K_POINTS automatic
  51 1 1 0 0 0

***************************************************************
Input file:graphene.bands.in
&INPUTPP
                  outdir = '/home/raman/graphene/g55mag/' ,
                  filband = 'graphenebands.dat' ,
            spin_component = 1 ,
                  lsym = .true. ,
/

***************************************************************
Input file:graphene.pdos.in
&inputpp
outdir='/home/raman/graphene/g55mag/'
Emin=-25.0, Emax=10.0, DeltaE=0.1
ngauss=1, degauss=0.02
/

***************************************************************
Input file:graphene.pp_spin.in
&INPUTPP
                  outdir = '/home/raman/graphene/g55mag/' ,
                  filplot = '/home/raman/graphene/g55mag/graphene-spin.plot' ,
                  plot_num = 6,
/
&PLOT
                     nfile = 1 ,
               weight(1) = 1.0,
                  fileout = '/home/raman/graphene/g55mag/graphene-spin.out' ,
                     iflag = 3 ,
            output_format = 3 ,
                     e1(1) = 4,
                     e1(2) = 0,
                     e1(3) = 0,
                     e2(1) = 0,
                     e2(2) = 10,
                     e2(3) = 0,
                     e3(1) = 0,
                     e3(2) = 0,
                     e3(3) = 5,
                     x0(1) = 0,
                     x0(2) = 0,
                     x0(3) = 0,
                        nx = 50 ,
                        ny = 50 ,
                        nz = 50 ,
/

The following pictures are the spin-up electronic density.

[ Last edited by xirainbow on 2009-8-6 at 22:22 ]

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