Add get_qm_corrections script for AEC and BAC lookup from RMG database

Author: calvinp0

arc/scripts/get_qm_corrections.py

@@ -0,0 +1,75 @@
+#!/usr/bin/env python3
+# encoding: utf-8
+
+"""
+Look up atom energy corrections (AEC) and bond additivity corrections (BAC)
+from the RMG quantum corrections database for a given level of theory.
+
+Run from the RMG conda environment so that Arkane is importable.
+
+Usage::
+
+    python get_qm_corrections.py input.yaml output.yaml
+
+Input YAML format::
+
+    matched_key: "LevelOfTheory(method='cbsqb3',software='gaussian')"
+    bac_type: p          # 'p', 'm', or null
+
+Output YAML format::
+
+    aec:
+        H: -0.499818
+        C: -37.78794
+    bac:
+        C-H: -0.06
+"""
+
+import re
+import sys
+
+from arkane.encorr.data import atom_energies, pbac, mbac
+from arkane.modelchem import LevelOfTheory
+
+from common import read_yaml_file, save_yaml_file
+
+
+def _lot_from_string(lot_str):
+    """Construct a LevelOfTheory from its repr string."""
+    # Extract keyword arguments from e.g. "LevelOfTheory(method='cbsqb3',software='gaussian')"
+    kwargs = dict(re.findall(r"(\w+)\s*=\s*'([^']*)'", lot_str))
+    return LevelOfTheory(**kwargs)
+
+
+def main(input_path, output_path):
+    """Look up AEC and BAC for the given level of theory key."""
+    params = read_yaml_file(input_path) or {}
+    matched_key = params.get('matched_key')
+    bac_type = params.get('bac_type')
+
+    result = {'aec': None, 'bac': None}
+
+    if not matched_key:
+        save_yaml_file(output_path, result)
+        return
+
+    lot = _lot_from_string(matched_key)
+
+    aec = atom_energies.get(lot)
+    if aec is not None:
+        result['aec'] = {str(k): float(v) for k, v in aec.items()}
+
+    if bac_type in ('p', 'm'):
+        bac_dict = pbac if bac_type == 'p' else mbac
+        bac = bac_dict.get(lot)
+        if bac is not None:
+            result['bac'] = {str(k): float(v) for k, v in bac.items()}
+
+    save_yaml_file(output_path, result)
+
+
+if __name__ == '__main__':
+    if len(sys.argv) != 3:
+        print(f'Usage: {sys.argv[0]} input.yaml output.yaml', file=sys.stderr)
+        sys.exit(1)
+    main(sys.argv[1], sys.argv[2])