diff --git a/atomistics/calculators/ase.py b/atomistics/calculators/ase.py
index 5b4d452f..e998cc84 100644
--- a/atomistics/calculators/ase.py
+++ b/atomistics/calculators/ase.py
@@ -107,7 +107,7 @@ def calc_static_with_ase(
     output_keys=OutputStatic.keys(),
 ):
     return OutputStatic(
-        **{k: getattr(ASEExecutor, k) for k in OutputStatic.fields()}
+        **{k: getattr(ASEExecutor, k) for k in OutputStatic.keys()}
     ).get(
         ASEExecutor(ase_structure=structure, ase_calculator=ase_calculator),
         *output_keys,
@@ -120,7 +120,7 @@ def _calc_md_step_with_ase(
     structure.calc = ase_calculator
     MaxwellBoltzmannDistribution(atoms=structure, temperature_K=temperature)
     ASEOutputMolecularDynamics = OutputMolecularDynamics(
-        **{k: getattr(ASEExecutor, k) for k in OutputMolecularDynamics.fields()}
+        **{k: getattr(ASEExecutor, k) for k in OutputMolecularDynamics.keys()}
     )
     cache = {q: [] for q in output_keys}
     for i in range(int(run / thermo)):
diff --git a/atomistics/calculators/qe.py b/atomistics/calculators/qe.py
index d48bdaf9..3048cf3d 100644
--- a/atomistics/calculators/qe.py
+++ b/atomistics/calculators/qe.py
@@ -208,7 +208,7 @@ def calc_static_with_qe(
         calculation_name=calculation_name, working_directory=working_directory
     )
     return OutputStatic(
-        **{k: getattr(QEStaticParser, k) for k in OutputStatic.fields()}
+        **{k: getattr(QEStaticParser, k) for k in OutputStatic.keys()}
     ).get(QEStaticParser(filename=output_file_name), *output_keys)
 
 
diff --git a/atomistics/workflows/elastic/workflow.py b/atomistics/workflows/elastic/workflow.py
index 16d564ba..5fbbba01 100644
--- a/atomistics/workflows/elastic/workflow.py
+++ b/atomistics/workflows/elastic/workflow.py
@@ -62,5 +62,5 @@ def analyse_structures(self, output_dict, output_keys=OutputElastic.keys()):
         self._data["e0"] = ene0
         self._data["A2"] = A2
         return OutputElastic(
-            **{k: getattr(ElasticProperties, k) for k in OutputElastic.fields()}
+            **{k: getattr(ElasticProperties, k) for k in OutputElastic.keys()}
         ).get(ElasticProperties(elastic_matrix=elastic_matrix), *output_keys)
diff --git a/atomistics/workflows/evcurve/debye.py b/atomistics/workflows/evcurve/debye.py
index abe9b9d7..50a79bdb 100644
--- a/atomistics/workflows/evcurve/debye.py
+++ b/atomistics/workflows/evcurve/debye.py
@@ -230,7 +230,7 @@ def get_thermal_properties(
     output_keys=OutputThermodynamic.keys(),
 ):
     return OutputThermodynamic(
-        **{k: getattr(DebyeThermalProperties, k) for k in OutputThermodynamic.fields()}
+        **{k: getattr(DebyeThermalProperties, k) for k in OutputThermodynamic.keys()}
     ).get(
         DebyeThermalProperties(
             fit_dict=fit_dict,
diff --git a/atomistics/workflows/evcurve/workflow.py b/atomistics/workflows/evcurve/workflow.py
index 177fcf96..d081868e 100644
--- a/atomistics/workflows/evcurve/workflow.py
+++ b/atomistics/workflows/evcurve/workflow.py
@@ -178,7 +178,7 @@ def analyse_structures(
         self._fit_dict = OutputEnergyVolumeCurve(
             **{
                 k: getattr(EnergyVolumeCurveProperties, k)
-                for k in OutputEnergyVolumeCurve.fields()
+                for k in OutputEnergyVolumeCurve.keys()
             }
         ).get(
             EnergyVolumeCurveProperties(
diff --git a/atomistics/workflows/phonons/workflow.py b/atomistics/workflows/phonons/workflow.py
index 2cbc2fcc..dc47ebd5 100644
--- a/atomistics/workflows/phonons/workflow.py
+++ b/atomistics/workflows/phonons/workflow.py
@@ -234,7 +234,7 @@ def analyse_structures(self, output_dict, output_keys=OutputPhonons.keys()):
         forces_lst = [output_dict[k] for k in sorted(output_dict.keys())]
         self.phonopy.forces = forces_lst
         self._phonopy_dict = OutputPhonons(
-            **{k: getattr(PhonopyProperties, k) for k in OutputPhonons.fields()}
+            **{k: getattr(PhonopyProperties, k) for k in OutputPhonons.keys()}
         ).get(
             PhonopyProperties(
                 phonopy_instance=self.phonopy,
@@ -296,7 +296,7 @@ def get_thermal_properties(
         return OutputThermodynamic(
             **{
                 k: getattr(PhonopyThermalProperties, k)
-                for k in OutputThermodynamic.fields()
+                for k in OutputThermodynamic.keys()
             }
         ).get(PhonopyThermalProperties(phonopy_instance=self.phonopy), *output_keys)
 
diff --git a/atomistics/workflows/quasiharmonic.py b/atomistics/workflows/quasiharmonic.py
index 13171c95..3cd6bc5b 100644
--- a/atomistics/workflows/quasiharmonic.py
+++ b/atomistics/workflows/quasiharmonic.py
@@ -115,7 +115,7 @@ def get_thermal_properties(
     return OutputThermodynamic(
         **{
             k: getattr(QuasiHarmonicThermalProperties, k)
-            for k in OutputThermodynamic.fields()
+            for k in OutputThermodynamic.keys()
         }
     ).get(
         QuasiHarmonicThermalProperties(