LWANNIER90: Difference between revisions

Revision as of 09:18, 24 August 2021

LWANNIER90 = .TRUE. | .FALSE.
Default: LWANNIER90 = .FALSE.

Description: LWANNIER90=.TRUE. switches on the interface between VASP and WANNIER90.

N.B.: This feature is only present if VASP is compiled with -DVASP2WANNIER90 or -DVASP2WANNIER90v2.

For LWANNIER90=.TRUE., VASP will write the input files for a preceding WANNIER90 run: wannier90.win, wannier90.mmn, wannier90.eig, wannier90.amn, and if LWRITE_UNK=.TRUE. wannier90.UNKp.s. This is done by running wannier_setup in library mode as described in Chapter 6 of the WANNIER90 manual. For documentation of these files and tags therein, please refer to the WANNIER90 manual.

The following cases may occur:

If wannier90.win does not exist, VASP will write the following template

num_wann = NBANDS

begin unit_cell_cart
  ... ... ...
  ... ... ...
  ... ... ...
end unit_cell_cart

begin atoms_cart
   ... ... ...
   ... ... ...
   ... ... ...
   ... ... ...  
end atoms_cart

mp_grid = .. .. ..

begin kpoints
   ... ... ...
   ... ... ...
   ... ... ...
   ... ... ...
end kpoints

Here, the unit_cell_cart, atoms_cart, and kpoints blocks, and mp_grid array, will be set in accordance with the setup of the VASP calculation. This basically corresponds to the information given in the POSCAR and KPOINTS files.

If the wannier90.win file already exists, VASP will only add the aforementioned information if it is not already present. This means that VASP will check, for instance, whether or not the wannier90.win file contains a kpoints block, and add one if not. Mind: If it finds a kpoints block, VASP will not check whether this block agrees with the k points used in the VASP calculation!

The user may create a wannier90.win file prior to running VASP with LWANNIER90=.TRUE., and specify any tag and/or block that is understood by wannier_setup and/or wannier_run. For instance, one can specify the projections block in the wannier90.win file that controls the initial guess for the maximally localized Wannier functions. Then, VASP writes the projections of the Bloch functions onto the relevant projectors to the wannier90.amn file. See Chapter 3 of the WANNIER90 manual for more information.

Related Tags and Sections

LWRITE_UNK, LWRITE_MMN_AMN, LWANNIER90_RUN, -DVASP2WANNIER90 or -DVASP2WANNIER90v2

Examples that use this tag

@@ Line 3: / Line 3: @@
 Description: {{TAG|LWANNIER90}}=.TRUE. switches on the interface between VASP and [http://www.wannier.org WANNIER90].
-'''N.B.''': At present the VASP2WANNIER90 interface works with WANNIER90 v1.2, not with WANNIER90 v2.0 (yet).
+'''N.B.''': This feature is only present if VASP is compiled with [[Precompiler_flags|-DVASP2WANNIER90 or -DVASP2WANNIER90v2]].
 ----
-For {{TAG|LWANNIER90}}=.TRUE., VASP will run <tt>wannier_setup</tt> in library mode (see Chapter 6 of the [http://www.wannier.org/doc/user_guide.pdf WANNIER90 manual]).
-The VASP2WANNIER90 interface will write the following files that WANNIER90 needs as input:
+For {{TAG|LWANNIER90}}=.TRUE., VASP will write the input files for a preceding WANNIER90 run: '''wannier90.win''', '''wannier90.mmn''', '''wannier90.eig''', '''wannier90.amn''', and if {{TAG|LWRITE_UNK}}=.TRUE. '''wannier90.UNKp.s'''. This is done by running <tt>wannier_setup</tt> in library mode as described in Chapter 6 of the [http://www.wannier.org/doc/user_guide.pdf WANNIER90 manual]. For documentation of these files and tags therein, please refer to the [http://www.wannier.org/doc/user_guide.pdf WANNIER90 manual].
-*wannier90.win
+The following cases may occur:
-:'''1'''. If this file does not exist, VASP will create it and write the following information onto it:
+* If '''wannier90.win''' does not exist, VASP will write the following template
   num_wann = {{TAG|NBANDS}}
@@ Line 35: / Line 35: @@
      ... ... ...
   end kpoints
-:Where the <tt>unit_cell_cart</tt>, <tt>atoms_cart</tt>, and <tt>kpoints</tt> blocks, and <tt>mp_grid</tt> array, will be set in accordance with the setup of the VASP calculation (''i.e.'', basically the information from the {{FILE|POSCAR}} and {{FILE|KPOINTS}} files). For the meaning of these tags and blocks please refer to the [http://www.wannier.org/doc/user_guide.pdf WANNIER90 manual].
+:Here, the <tt>unit_cell_cart</tt>, <tt>atoms_cart</tt>, and <tt>kpoints</tt> blocks, and <tt>mp_grid</tt> array, will be set in accordance with the setup of the VASP calculation. This basically corresponds to the information given in the {{FILE|POSCAR}} and {{FILE|KPOINTS}} files.
-:'''2'''. If the wannier90.win file already exists, VASP will only add the the aforementioned information insofar it is not already present. This means that VASP will check, for instance, whether or not the wannier90.win file contains a <tt>kpoints</tt>-block, and add one if not. If it finds a <tt>kpoints</tt>-block, however, it will not check whether this block tallies with the present set of '''k'''-points used in the VASP calculation!
+* If the '''wannier90.win''' file already exists, VASP will only add the aforementioned information if it is not already present. This means that VASP will check, for instance, whether or not the '''wannier90.win''' file contains a <tt>kpoints</tt> block, and add one if not. '''Mind''': If it finds a <tt>kpoints</tt> block, VASP will not check whether this block agrees with the k points used in the VASP calculation!
-:'''3'''. The user may create a wannier90.win file prior to running VASP and executing the VASP2WANNIER90 interface, and specify any tag and/or block that is understood by <tt>wannier_setup</tt> and/or <tt>wannier_run</tt>. The most common example of this is probably the <tt>projections</tt>-block that specifies the initial guess for the maximally localized Wannier functions (see Chapter 3 of the [http://www.wannier.org/doc/user_guide.pdf WANNIER90 manual]).
-*wannier90.mmn
-*wannier90.eig
-*wannier90.amn
-:If a <tt>projections</tt>-block has been specified in the wannier90.win file, VASP writes the projections of the Bloch functions onto the relevant projectors to the wannier90.amn file (see Chapter 3 of the [http://www.wannier.org/doc/user_guide.pdf WANNIER90 manual]).
-*wannier90.UNKp.s
-:If {{TAG|LWRITE_UNK}}=.TRUE. is set in the {{FILE|INCAR}} file, VASP writes the cell-periodic part of the wave functions in spin-channel ''s'' at '''k'''-point ''p'' to the file wannier90.UNKp.s.
-----
-'''Mind''': VASP needs to be compiled with the following additional precompiler flag:
- -DVASP2WANNIER90
+The user may create a '''wannier90.win''' file prior to running VASP with {{TAG|LWANNIER90}}=.TRUE., and specify any tag and/or block that is understood by <tt>wannier_setup</tt> and/or <tt>wannier_run</tt>. For instance, one can specify the <tt>projections</tt> block in the '''wannier90.win''' file that controls the initial guess for the maximally localized Wannier functions.
+Then, VASP writes the projections of the Bloch functions onto the relevant projectors to the '''wannier90.amn''' file. See Chapter 3 of the [http://www.wannier.org/doc/user_guide.pdf WANNIER90 manual] for more information.
-and the variable <tt>LIB</tt> in the [[Installing VASP|makefile]] must contain an entry that points to <tt>libwannier.a</tt>.
-For instance:
- LIB     = -L../vasp.5.lib -ldmy  \
-      ../vasp.5.lib/linpack_double.o $(SCA) $(LAPACK) $(BLAS)
-might be changed to
- LIB     = -L../vasp.5.lib -ldmy  \
-      ../vasp.5.lib/linpack_double.o ../wannier90-1.2/libwannier.a $(SCA) $(LAPACK) $(BLAS)
-depending on where you have installed WANNIER90, obviously.
+----
@@ Line 69: / Line 49: @@
 {{TAG|LWRITE_MMN_AMN}},
 {{TAG|LWANNIER90_RUN}},
-[[Installing VASP|Compiling VASP]]
+[[Precompiler_flags|-DVASP2WANNIER90 or -DVASP2WANNIER90v2]]
 {{sc|LWANNIER90|Examples|Examples that use this tag}}