Calculation of metal, e.g., Al.

STEP 1

Optimization of lattice constant.

&control
    calculation = 'vc-relax'
    prefix = 'al'
    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=2, celldm(1) =7.652, 
    nat=1, ntyp=1,
    ecutwfc=40
    ecutrho=320
    occupations='smearing',smearing='gaussian',degauss=0.01
/
&electrons
    conv_thr=1e-8
/
&ions
/
&cell
    cell_dofree='ibrav'
/
ATOMIC_SPECIES
 Al  26.981539  Al.pbe-n-kjpaw_psl.1.0.0.UPF
ATOMIC_POSITIONS (alat)
 Al 0.00 0.00 0.00
K_POINTS (automatic)
  10 10 10 0 0 0

Notes:

1. ecutrho is the energy cutoff for charge density, which is in default 4 times of ecutwfc.
2. smearing is necessary to avoid the oscillaion, which is harmful to the convergence.

And you can find the final structure in the .out file.

Begin final coordinates
     new unit-cell volume =    111.12142 a.u.^3 (    16.46650 Ang^3 )
     density =      2.72091 g/cm^3

CELL_PARAMETERS (alat=  7.65200000)
  -0.498671221   0.000000000   0.498671221
   0.000000000   0.498671221   0.498671221
  -0.498671221   0.498671221   0.000000000

ATOMIC_POSITIONS (alat)
Al            0.0000000000        0.0000000000        0.0000000000
End final coordinates

The density of fcc Al is 2.72091 $g/cm^{3}$ (which is 2.7 in ref), and the lattice constant is 7.63166 $Bohr$ (7.652 in ref).

STEP 2

Self-consistent calculations to obtain the wfc.

&control
    calculation = 'scf'
    restart_mode='from_scratch'
    prefix = 'al'
    outdir = './outdir'
    pseudo_dir = '/BIGDATA1/ac_iphy_jrsun_1/soft/QE/SSSP'
    ! pseudo_dir = '/home/anonymous/quantumEspresso_2019/SSSP_precision_pseudos'
/
&system
    ibrav=2, celldm(1) =7.631664366184, 
    nat=1, ntyp=1,
    ecutwfc=40
    ecutrho=320
    occupations='smearing',smearing='gaussian',degauss=0.01
/
&electrons
    conv_thr=1e-8
/
ATOMIC_SPECIES
 Al  26.981539  Al.pbe-n-kjpaw_psl.1.0.0.UPF
ATOMIC_POSITIONS (alat)
 Al 0.00 0.00 0.00
K_POINTS (automatic)
  10 10 10 0 0 0

STEP 3

The k-point interpolation method to obtain dos. (enough dense k-grid)

&control
    calculation = 'nscf'
    restart_mode='from_scratch'
    prefix = 'al'
    outdir = './outdir'
    pseudo_dir = '/BIGDATA1/ac_iphy_jrsun_1/soft/QE/SSSP'
    ! pseudo_dir = '/home/anonymous/quantumEspresso_2019/SSSP_precision_pseudos'
/
&system
    ibrav=2, celldm(1) =7.631664366184, 
    nat=1, ntyp=1,
    ecutwfc=40
    ecutrho=320
    occupations='smearing',smearing='gaussian',degauss=0.01
/
&electrons
    conv_thr=1e-8
/
ATOMIC_SPECIES
 Al  26.981539  Al.pbe-n-kjpaw_psl.1.0.0.UPF
ATOMIC_POSITIONS (alat)
 Al 0.00 0.00 0.00
K_POINTS (automatic)
 30 30 30 0 0 0

STEP 4

Use the dos.x to obtain density of states.

&DOS
    prefix='al'
    outdir='./outdir/'
    fildos='al.dos.dat'
    emin=-15
    emax=35
/

And below is the dos of Al.