====== Using Wannier90 with the VASP DARWIN ======

This outlines the compilation of Wannier90 and how to use the Wannier90 library in VASP using Intel compiler.

====== Build Wannier90 ======

Prepare a Wannier90 folder.

First, set up VALET package:
<code bash>
[user@login00.darwin ~]$ vpkg_require openmpi/4.1.0:intel-2020
</code>

Copy the make.inc file in the config folder.
<code bash>
[user@login00.darwin ~]$ cp config/make.inc.ifort make.inc
</code>
Make the following changes in the make.inc file.
<code bash>
MPIF90=mpif90
LIBDIR =
LIBS   = -mkl=sequential
</code>
Build a library:
<code bash>
[user@login00.darwin ~]$ make lib
</code>
You will see the **libwannier.a** file in your current folder if you successfully compiled.
====== Build VASP with Wannier90 ======
Go to the VASP src folder (see the Software-VASP section for VASP compilation).

Add the following to the makefile.include file.
<code bash>
WANNIER90_ROOT ?= "Your Wannier90 work folder should contain the libwannier.a file."
LLIBS          += -L$(WANNIER90_ROOT)/lib -lwannier
</code>
Compile VASP:
<code bash>
[user@login00.darwin ~]$ make
</code>

Add "LWANNIER90 = .TRUE." to your INCAR; this will produce Wannier90* files if you have successfully installed it.