Updated documentation of the hk converter

doc/guide/conversion.rst

@@ -188,8 +188,8 @@ A general H(k)
 In addition to the more complicated Wien2k converter,
 :program:`DFTTools` contains also a light converter. It takes only
 one inputfile, and creates the necessary hdf outputfile for
-the DMFT calculation. The header of this input file has to have the
+the DMFT calculation. The header of this input file has a defined
-following format:
+format, an example is the following:
 
 .. literalinclude:: images_scripts/case.hk
 
@@ -197,10 +197,64 @@ The lines of this header define
 		    
 #. Number of :math:`\mathbf{k}`-points used in the calculation
 #. Electron density for setting the chemical potential
-#. Number of correlated atoms in the unit cell
+#. Number of total atomic shells in the hamiltonian matrix. In short,
-#. The next line contains four numbers: index of the atom, index
+   this gives the number of lines described in the following. IN the
-   of the correlated shell, :math:`l` quantum number, dimension
+   example file give above this number is 2.
-   of this shell. Repeat this line for each correlated atom.
+#. The next line(s) contain four numbers each: index of the atom, index
+   of the equivalent shell, :math:`l` quantum number, dimension
+   of this shell. Repeat this line for each atomic shell, the number
+   of the shells is given in the previous line.
+
+   In the example input file given above, we have two inequivalent
+   atomic shells, one on atom number 1 with a full d-shell (dimension 5),
+   and one on atom number 2 with one p-shell (dimension 3).
+
+   Other examples for these lines are:
+
+   #. Full d-shell in a material with only one correlated atom in the
+      unit cell (e.g. SrVO3). One line is sufficient and the numbers
+      are `1 1 2 5`.
+   #. Full d-shell in a material with two equivalent atoms in the unit
+      cell (e.g. FeSe): You need two lines, one for each equivalent
+      atom. First line is `1 1 2 5`, and the second line is
+      `2 1 2 5`. The only difference is the first number, which tells on
+      which atom the shell is located. The second number is the
+      same in both lines, meaning that both atoms are equivalent.
+   #. t2g orbitals on two non-equivalent atoms in the unit cell: Two
+      lines again. First line is `1 1 2 3`, second line `2 2 2 3`. The
+      difference to the case above is that now also the second number
+      differs. Therefore, the two shells are treated independently in
+      the calculation.
+   #. d-p Hamiltonian in a system with two equivalent atoms each in
+      the unit cell (e.g. FeSe has two Fe and two Se in the unit
+      cell). You need for lines. First line `1 1 2 5`, second
+      line
+      `2 1 2 5`. These two lines specify Fe as in the case above. For the p
+      orbitals you need line three as `3 2 1 3` and line four
+      as `4 2 1 3`. We have 4 atoms, since the first number runs from 1 to 4,
+      but only two inequivalent atoms, since the second number runs
+      only form 1 to 2.
+   
+   Note that the total dimension of the hamiltonian matrices that are
+   read in is the sum of all shell dimensions that you specified. For
+   example number 4 given above we have a dimension of 5+5+3+3=16. It is important
+   that the order of the shells that you give here must be the same as
+   the order of the orbitals in the hamiltonian matrix. In the last
+   example case above the code assumes that matrix index 1 to 5
+   belongs to the first d shell, 6 to 10 to the second, 11 to 13 to
+   the first p shell, and 14 to 16 the second p shell. 
+   
+#. Number of correlated shells in the hamiltonian matrix, in the same
+   spirit as line 3.
+
+#. The next line(s) contain six numbers: index of the atom, index
+   of the equivalent shell, :math:`l` quantum number, dimension
+   of the correlated shells, a spin-orbit parameter, and another
+   parameter defining interactions. Note that the latter two
+   parameters are not used at the moment in the code, and only kept
+   for compatibility reasons. In our example file we use only the
+   d-shell as correlated, that is why we have only one line here.
+      
 #. The last line contains several numbers: the number of irreducible
    representations, and then the dimensions of the irreps. One
    possibility is as the example above, another one would be 2

doc/guide/images_scripts/case.hk

@@ -1,5 +1,8 @@
-64        ! number of k-points
+64          ! number of k-points
-1.0       ! Electron density
+1.0         ! Electron density
-1         ! number of correlated atoms
+2           ! number of total atomic shells
-1 1 2 5   ! iatom, isort, l, dimension
+1 1 2 5     ! iatom, isort, l, dimension
-1 5       ! # of ireps, dimension of irep
+2 2 1 3     ! iatom, isort, l, dimension
+1           ! number of correlated shells
+1 1 2 5 0 0 ! iatom, isort, l, dimension, SO, irep
+1 5         ! # of ireps, dimension of irep

python/converters/hk_converter.py

@@ -121,7 +121,7 @@ class HkConverter(ConverterTools):
             # corresponds to index R in formulas
             # now read the information about the shells (atom, sort, l, dim, SO
             # flag, irep):
-            corr_shell_entries = ['atom', 'sort', 'l', 'dim', 'SO', 'irep']
+            corr_shell_entries = ['atom', 'sort', 'l', 'dim','SO','irep']
             corr_shells = [{name: int(val) for name, val in zip(
                 corr_shell_entries, R)} for icrsh in range(n_corr_shells)]