quantum-espresso/PP/Doc/INPUT_wannier2pw.def

input_description -distribution {Quantum ESPRESSO} -package PWscf -program wannier2pw.x {

    toc {}

    intro {

        @b {Purpose of wannier2pw.x:}
           Interface with wannier90 code to construct maximally localized Wannier functions
           that can be used in pw.x calculations for DFT+U.

           The code reads the _u.mat (_u_dis.mat) file which is generated by the wannier90.x program.
           Then, it builds the Bloch sums of Wannier functions and writes them on disk as .hub files
           in the temporary directory. Then these files are read by the pw.x program to perform the 
           DFT+U calculations using these Wannier functions as Hubbard projectors.
          
        @b {Structure of the input data:}
        ============================

           @b &INPUTPP
             ...
           @b /
    }

    namelist INPUTPP {

        var prefix -type CHARACTER {
            info { 
                prefix of files saved by program pw.x
            }
        }

        var outdir -type CHARACTER {
            info {
                directory containing the input data, i.e. the same as in pw.x
            }
            default {
                value of the @tt ESPRESSO_TMPDIR environment variable if set;
                current directory ('./') otherwise
            }
        }

        var seedname -type STRING {
            info {
                Seedname, same as for the wannier90 calculation.
            }
            default { 'wannier' }
        }

        var spin_component -type STRING {
            info {
                Spin component.
                'up': spin up for collinear spin calculation
                'down': spin down for collinear spin calculation
                'none': for no-spin or non-collinear calculation
            }
            default { 'none' }
        }

        var hubbard -type LOGICAL {
            info {
                Set to .true. to use the interface between Wannier90 and PW. This will use the 
                Wannier functions as a basis to build the Hubbard projectors for DFT+U.
            }
            default { .FALSE. }
        }

        var exclude_ks_bands -type INTEGER {
            info {
                This variable is used only when hubbard = .true. This variable specifies 
                how many lowest-lying Kohn-Sham bands must be excluded from the summation
                when building the Wannier functions using Umn matrices from Wannier90 
                (those bands which are below the energy where the wannierization starts)
            }
            default { 0 }
        }

        var wan2hub(i) -type LOGICAL {
            info {
                Set wan2hub(i) to .true. for those Wannier functions (i) which you want to use 
                as a basis to build the Hubbard projectors for DFT+U calculations. Note that
                the total number of selected Wannier functions must match the expected
                number of basis functions (e.g. 5 for d states, 3 for p states, etc per atom).
                In order to selected the Wannier functions, one has to inspect the output of 
                Wannier90 calculations and see in which oredr the Wannier functions were generated.
            }
            default { .FALSE. }
        } 

    }
}