Merge pull request #143 from jkarp314/unstable

optionally give Fermi energy in Wannier90 converter

doc/guide/conv_W90.rst

@@ -84,6 +84,8 @@ In our `Pnma`-LaVO\ :sub:`3` example, for instance, we could use::
 where the ``x=-1,1,0`` option indicates that the V--O bonds in the octahedra are
 rotated by (approximatively) 45 degrees with respect to the axes of the `Pbnm` cell.
 
+The last line of :file:`seedname.inp` is the DFT Fermi energy (in eV), which is subtracted from the onsite terms in the :file:`seedname_hr.dat` file. This is recommended since some functions in DFTTools  implicitly assume a Fermi energy of 0 eV. 
+
 The converter will analyse the matrix elements of the local Hamiltonian
 to find the symmetry matrices `rot_mat` needed for the global-to-local
 transformation of the basis set for correlated orbitals

doc/guide/images_scripts/LaVO3_w90.inp

@@ -5,3 +5,4 @@
  1  0  2  3  0  0       # atom, sort, l, dim, SO, irep
  2  0  2  3  0  0       # atom, sort, l, dim, SO, irep
  3  0  2  3  0  0       # atom, sort, l, dim, SO, irep
+0.0                     # DFT Fermi Energy (optional)

python/converters/wannier90_converter.py

@@ -142,6 +142,10 @@ class Wannier90Converter(ConverterTools):
             # l, dim, SO flag, irep):
             corr_shells = [{name: int(val) for name, val in zip(
                 corr_shell_entries, R)} for icrsh in range(n_corr_shells)]
+            try:
+                self.fermi_energy = R.next()
+            except:
+                self.fermi_energy = 0.
         except StopIteration:  # a more explicit error if the file is corrupted.
             mpi.report(self._name + ": reading input file %s failed!" %
                        self.inp_file)
@@ -443,6 +447,9 @@ class Wannier90Converter(ConverterTools):
                             "Inconsistent indices for R vector n. %s" % ir)
 
                 # fill h_of_r with the matrix elements of the Hamiltonian
+                if not numpy.any(rcurr) and ii == jj:
+                    h_of_r[ir][ii, jj] = complex(float(cline[5]) - self.fermi_energy, float(cline[6]))
+                else:
                     h_of_r[ir][ii, jj] = complex(float(cline[5]), float(cline[6]))
 
         except ValueError:

test/LaVO3-Pnma_ef.inp

@@ -0,0 +1,8 @@
+  0  3 2 3
+  8.0
+  4
+  0  0  2  3  0  0
+  1  0  2  3  0  0
+  2  0  2  3  0  0
+  3  0  2  3  0  0
+10.3

test/test_w90_ef.py

@@ -0,0 +1,25 @@
+import unittest
+import numpy as np
+import sys
+sys.path.insert(1, '../python/converters/')
+from wannier90_converter import Wannier90Converter
+from triqs_dft_tools import SumkDFT
+
+class test_w90_conv(unittest.TestCase):
+
+    def test_hopping(self):
+
+        conv1 = Wannier90Converter(seedname='LaVO3-Pnma')
+        conv1.convert_dft_input()
+        SK1 = SumkDFT(hdf_file='LaVO3-Pnma.h5')
+
+        conv2 = Wannier90Converter(seedname='LaVO3-Pnma_ef')
+        conv2.convert_dft_input()
+        SK2 = SumkDFT(hdf_file='LaVO3-Pnma_ef.h5')
+
+        for ik in range(SK1.n_k):
+            self.assertTrue(np.all(SK1.hopping[ik,0] - conv2.fermi_energy*np.identity(SK1.n_orbitals[ik][0]) - SK2.hopping[ik,0] < 1e-12))
+                             
+if __name__ == '__main__':
+    unittest.main()
+