Calculation of spin-polarized $\alpha-Fe$.
STEP 1
First, we perform the optimization of lattice constant.
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| &control
calculation = 'vc-relax'
prefix = 'fe'
outdir = './outdir'
pseudo_dir = '/BIGDATA1/ac_iphy_jrsun_1/soft/QE/SSSP'
! pseudo_dir = '/home/anonymous/quantumEspresso_2019/SSSP_precision_pseudos'
etot_conv_thr = 1e-6
forc_conv_thr = 1e-5
/
&system
ibrav=3, celldm(1) =5.416911045,
nat=1, ntyp=1,
ecutwfc=40
ecutrho=320
occupations='smearing',smearing='marzari-vanderbilt',degauss=0.01
nspin = 2
starting_magnetization(1)=0.1
/
&electrons
conv_thr=1e-8
/
&ions
/
&cell
cell_dofree='ibrav'
/
ATOMIC_SPECIES
Fe 55.845 Fe.pbe-spn-kjpaw_psl.0.2.1.UPF
ATOMIC_POSITIONS (alat)
Fe 0.00 0.00 0.00
K_POINTS (automatic)
8 8 8 0 0 0
|
New tags:
ibrav=3: corresponding to body center cubic. nspin=2: collinear spin polarized.starting_magnetization(1)=0.1: the origin M of first type atom is set to be 0.1 $\mu_{B}$.
And we can find below in the output.
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| Begin final coordinates
new unit-cell volume = 66.16346 a.u.^3 ( 9.80441 Ang^3 )
density = 9.45827 g/cm^3
CELL_PARAMETERS (alat= 5.41691104)
0.470364324 0.470364324 0.470364324
-0.470364324 0.470364324 0.470364324
-0.470364324 -0.470364324 0.470364324
ATOMIC_POSITIONS (alat)
Fe 0.0000000000 0.0000000000 0.0000000000
End final coordinates
|
The optimized lattice constant is 5.0958 Bohr ( 5.4169 in ref).
STEP 2
Do the scf.
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| &control
calculation = 'scf'
restart_mode='from_scratch'
prefix = 'fe'
outdir = './outdir'
pseudo_dir = '/BIGDATA1/ac_iphy_jrsun_1/soft/QE/SSSP'
! pseudo_dir = '/home/anonymous/quantumEspresso_2019/SSSP_precision_pseudos'
/
&system
ibrav=3, celldm(1) =5.095843399,
nat=1, ntyp=1,
ecutwfc=40
ecutrho=320
occupations='smearing',smearing='marzari-vanderbilt',degauss=0.01
nspin = 2
starting_magnetization(1)=0.1
/
&electrons
conv_thr=1e-8
/
ATOMIC_SPECIES
Fe 55.845 Fe.pbe-spn-kjpaw_psl.0.2.1.UPF
ATOMIC_POSITIONS (alat)
Fe 0.00 0.00 0.00
K_POINTS (automatic)
10 10 10 0 0 0
|
In the output, the magnetic moment is obtained.
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| Magnetic moment per site:
atom: 1 charge: 14.3011 magn: 1.9522 constr: 0.0000
|
Besides, we can find the range of the band (energy).
STEP 3
Do the nscf.
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| &control
calculation = 'nscf'
restart_mode='from_scratch'
prefix = 'fe'
outdir = './outdir'
pseudo_dir = '/BIGDATA1/ac_iphy_jrsun_1/soft/QE/SSSP'
! pseudo_dir = '/home/anonymous/quantumEspresso_2019/SSSP_precision_pseudos'
/
&system
ibrav=3, celldm(1) =5.09578335795351,
nat=1, ntyp=1,
ecutwfc=40
ecutrho=320
occupations='smearing',smearing='marzari-vanderbilt',degauss=0.01
nspin = 2
starting_magnetization(1)=0.1
/
&electrons
conv_thr=1e-8
/
ATOMIC_SPECIES
Fe 55.845 Fe.pbe-spn-kjpaw_psl.0.2.1.UPF
ATOMIC_POSITIONS (alat)
Fe 0.00 0.00 0.00
K_POINTS (automatic)
20 20 20 0 0 0
|
STEP 4
Calculate the density of states.
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| &DOS
prefix='fe'
outdir='./outdir/'
fildos='fe.dos.dat'
emin=-65
emax=50
/
|
