add band example

examples/ex05-band-al.py

@@ -0,0 +1,43 @@
+from ase.build import bulk, fcc111
+from ase.visualize import view
+from xespresso import Espresso
+import matplotlib.pyplot as plt
+
+
+atoms = fcc111("Al", size=(1, 1, 2), vacuum=4.0)
+pseudopotentials = {
+    "Al": "Al.pbe-n-rrkjus_psl.1.0.0.UPF",
+}
+calc = Espresso(
+    pseudopotentials=pseudopotentials,
+    label="scf/al",
+    ecutwfc=40,
+    occupations="smearing",
+    degauss=0.01,
+    kpts=(4, 4, 1),
+    debug=True,
+)
+atoms.calc = calc
+e = atoms.get_potential_energy()
+calc.read_results()
+e = calc.results["energy"]
+fermi_energy = calc.get_fermi_level()
+print("Energy: {0:1.3f}".format(e))
+# ===============================================================================
+bandpath = atoms.cell.bandpath()
+calc = Espresso(
+    calculation="bands",
+    label="scf/al",
+    pseudopotentials=pseudopotentials,
+    ecutwfc=40,
+    occupations="smearing",
+    degauss=0.01,
+    kpts=bandpath,
+    debug=True,
+)
+atoms.calc = calc
+calc.run(atoms)
+# =================================================
+bs = calc.band_structure()
+bs.reference = fermi_energy
+bs.plot()

xespresso/xespresso.py

@@ -311,6 +311,7 @@ def read_results(self):
         except Exception as e:
             logger.debug("Read output: %s, failed! %s" % (pwo, e))
         self.results["convergence"] = convergence
+        self.results["label"] = self.label
         # logger.debug('Read result failed!')
         # pwos = [file for file in os.listdir(self.directory) if pwo in file]
         # output = None