This tutorial explains how to obtain the maximally localized Wannier function of an anthracene crystal.
First of all, optimize the atomic positions as well as the cell parameters.
A single point (SCF) calculation is performed by using the optimized structure (using the input filec28h20.scf.in).
To prepare for the calculation of the max. loc. Wannier function, non-SCF calculation using a k-point set generated by using utility/kmesh.pl. To generate, for instance, a 4 x 4 x 4 k-point set, execute
kmesh.pl 4 4 4
and use the generated k-points to create the input file for the non-SCF calculation (c28h20.nscf.in)
After the non-SCF calculation, *.win to be generated first and one uses the following commands. Let us name c28h20.win and then execute
wannier90.x -pp c28h20
Then execute pw2wannier90.x as other commands in the QE suite such as pw.x using the input file (e.g., c28h20.pw2wan). Note the same number of cores should be used as the SCF/Non-SCF calculation if wf_collect=.false.
Finally execute wannier90.x
wannier90.x c28h20
Note Wannier90 (<3) is not parallelized and it is not necessary to use mpirun nor the same number of cores for SCF and non-SCF calculations.