    ------------------------------------------------------------------------
    INPUT FILE DESCRIPTION

    Program: dos.x / PWscf / Quantum Espresso
    ------------------------------------------------------------------------

    Purpose of dos.x:
        calculates the Density of States (DOS)
        (separated into up and down components for DSDA)

    Structure of the input data:
    ============================

       &DOS
         ...
       /
    IMPORTANT: since v.5 namelist name is &dos and no longer &inputpp

    ========================================================================
    NAMELIST: &DOS

       +--------------------------------------------------------------------
       Variable:       prefix

       Type:           CHARACTER
       Default:        'pwscf'
       Description:    prefix of input file produced by pw.x
                       (wavefunctions are not needed)
       +--------------------------------------------------------------------

       +--------------------------------------------------------------------
       Variable:       outdir

       Type:           CHARACTER
       Description:    directory containing the input data,
                       i.e. the same as in pw.x
       Default:        value of the ESPRESSO_TMPDIR environment variable if set;
                       current directory ('./') otherwise
       +--------------------------------------------------------------------

       +--------------------------------------------------------------------
       Variable:       ngauss

       Type:           INTEGER
       Default:        0
       Status:         optional
       Description:    Type of gaussian broadening:

                           =  0  Simple Gaussian (default)

                           =  1  Methfessel-Paxton of order 1

                           = -1  Marzari-Vanderbilt "cold smearing"

                           =-99  Fermi-Dirac function
       +--------------------------------------------------------------------

       +--------------------------------------------------------------------
       Variable:       degauss

       Type:           REAL
       Description:    gaussian broadening, Ry (not eV!)          see below
       +--------------------------------------------------------------------

       +--------------------------------------------------------------------
       Variables:      Emin, Emax

       Type:           REAL
       Default:        band extrema
       Description:    min, max energy (eV) for DOS plot. If unspecified, the
                       lower and/or upper band value, plus/minus 3 times the
                       value of the gaussian smearing if present, will be used.
       +--------------------------------------------------------------------

       +--------------------------------------------------------------------
       Variable:       DeltaE

       Type:           REAL
       Description:    energy grid step (eV)
       +--------------------------------------------------------------------

       +--------------------------------------------------------------------
       Variable:       fildos

       Type:           CHARACTER
       Default:        "prefix".dos
       Description:    output file containing DOS(E)
       +--------------------------------------------------------------------

    ===END OF NAMELIST======================================================

    :::: Notes

       ::: Output

          The total DOS (states/eV plotted vs E in eV) is written to file "fildos"

       ::: Important !

          The tetrahedron method is used if

              - the input data file has been produced by pw.x using the option
                occupations='tetrahedra', AND

              - a value for degauss is not given as input to namelist &dos

          Gaussian broadening is used in all other cases:

              - if degauss is set to some value in namelist &dos, that value
                (and the optional value for ngauss) is used

              - if degauss is NOT set to any value in namelist &dos, the
                value of degauss and of ngauss are read from the input data
                file (they will be the same used in the pw.x calculations)

              - if degauss is NOT set to any value in namelist &dos, AND
                there is no value of degauss and of ngauss in the input data
                file, degauss=DeltaE (in Ry) and ngauss=0 will be used