Removed reliance on files being named OUTCAR

Removed use of ase's VASP Calculator, which has the filenames
hardcoded (and that is OK for ase, as the job of this class is
to run VASP)

Author: WardLT

dfttopif/parsers/vasp.py

@@ -2,8 +2,8 @@
 
 from .base import DFTParser, Value_if_true, InvalidIngesterException
 import os
-from ase.calculators.vasp import Vasp
-from ase.io.vasp import read_vasp, read_vasp_out
+import re
+from ase.io.vasp import read_vasp_out
 from pypif.obj import Value, FileReference
 from dftparse.vasp.outcar_parser import OutcarParser
 from dftparse.vasp.eigenval_parser import EigenvalParser
@@ -26,7 +26,7 @@ def _find_file(name):
             for f in self._files:
                 if os.path.basename(f).upper().startswith(name):
                     if my_file is not None:
-                        raise InvalidIngesterException('Found more than one %s file'.format(name))
+                        raise InvalidIngesterException('Found more than one {} file'.format(name))
                     my_file = f
             return my_file
         self.outcar = _find_file('OUTCAR')
@@ -121,7 +121,6 @@ def get_xc_functional(self):
                 if "TITEL" in line:
                     words = line.split()
                     return Value(scalars=[Scalar(value=words[2])])
-                    break
 
     def get_pp_name(self):
         # Open up the OUTCAR
@@ -135,10 +134,7 @@ def get_pp_name(self):
                     words = line.split()
                     pp.append(words[3])
             return Value(vectors=[[Scalar(value=x) for x in pp]])
-                
-        # Error handling: TITEL not found
-        raise Exception('TITEL not found')
-        
+
     def get_KPPRA(self):
         # Open up the OUTCAR
         with open(self.outcar) as fp:
@@ -167,15 +163,46 @@ def get_KPPRA(self):
             else:
                 return Value(scalars=[Scalar(value=NI*NIRK)])
 
-                
-        # Error handling: NKPTS or NIONS not found
-        raise Exception('NIONS, irredicuble or Coordinates not found')
-
     def _is_converged(self):
-        return self._call_ase(Vasp().read_convergence, os.path.dirname(self.outcar))
+        # Follows the procedure used by qmpy, but without reading the whole file into memory
+        #   Source: https://github.com/wolverton-research-group/qmpy/blob/master/qmpy/analysis/vasp/calculation.py
+
+        with open(self.outcar) as fp:
+            # Part 1: Determine the NELM
+            nelm = None
+            for line in fp:
+                if line.startswith("   NELM   ="):
+                    nelm = int(line.split()[2][:-1])
+                    break
+
+            # If we don't find it, tell the user
+            if nelm is None:
+                raise Exception('NELM not found. Cannot tell if this result is converged')
+
+            # Now, loop through the file. What we want to know is whether the last ionic
+            #   step of this file terminates because it converges or because we hit NELM
+            re_iter = re.compile('([0-9]+)\( *([0-9]+)\)')
+            converged = False
+            for line in fp:
+                # Count the ionic steps
+                if 'Iteration' in line:
+                    ionic, electronic = map(int, re_iter.findall(line)[0])
+
+                # If the loop is finished, mark the number of electronic steps
+                if 'aborting loop' in line:
+                    converged = electronic < nelm
+
+            return converged
 
     def get_total_energy(self):
-        return Property(scalars=[Scalar(value=self._call_ase(Vasp().read_energy, os.path.dirname(self.outcar))[0])], units='eV')
+        with open(self.outcar) as fp:
+            last_energy = None
+            for line in fp:
+                if line.startswith('  free  energy   TOTEN'):
+                    last_energy = float(line.split()[4])
+        if last_energy is None:
+            return None
+        return Property(scalars=[Scalar(value=last_energy)], units='eV')
 
     def get_version_number(self):
         # Open up the OUTCAR