Add option to change xTB parameterisation version and temperature (du…

…artegroup#252)

* etemp and gfn options for xTB

* fix tests

* update changelog

autode/config.py

@@ -337,6 +337,15 @@ class XTB:
         # Force constant used for harmonic restraints in constrained
         # optimisations (Ha/a0)
         force_constant = 2
+        #
+        # Electronic temperature for all calculations (Kelvin)
+        # None means unset (default), set to 300.0 to have 300K for example
+        electronic_temp = None
+        #
+        # Version of xTB hamiltonian parameterisation: 0,1 or 2
+        # corresponding to GFN0-xTB, GFN1-xTB, GFN2-xTB respectively
+        # When unset, uses the default
+        gfn_version = None
 
     class MOPAC:
         # ---------------------------------------------------------------------

autode/wrappers/XTB.py

@@ -24,6 +24,8 @@ def __init__(self):
         )
 
         self.force_constant = Config.XTB.force_constant
+        self.electronic_temp = Config.XTB.electronic_temp
+        self.gfn_version = Config.XTB.gfn_version
 
     def __repr__(self):
         return f"XTB(available = {self.is_available})"
@@ -166,6 +168,10 @@ def execute(self, calc):
             "--uhf",
             str(calc.molecule.mult - 1),
         ]
+        if self.electronic_temp is not None:
+            flags.extend(["--etemp", str(float(self.electronic_temp))])
+        if self.gfn_version is not None:
+            flags.extend(["--gfn", str(self.gfn_version)])
 
         if isinstance(calc.input.keywords, OptKeywords):
             if calc.input.keywords.max_opt_cycles is not None:

doc/changelog.rst

@@ -15,6 +15,7 @@ Usability improvements/Changes
 ******************************
 - Adds full usability of autodE on Windows, including parallelisation with :code:`loky`
 - Optional timeout for graph isomorphism test in Windows, turned on by :code:`Config.use_experimental_timeout=True` (default behaviour kept for Linux/macOS)
+- The electronic temperature and the version of parameterisation for xTB calculations are made configurable
 - A NEB :code:`Image` now derives from a :code:`Species` superclass
 - Modifies NEB :code:`Image` constructor to be formed from an image
 - Defines named constructors (:code:`from_endpoints(...)`, :code:`from_list(...)`) for :code:`NEB`

tests/test_wrappers/test_xtb.py

@@ -4,7 +4,7 @@
 import os
 import pytest
 
-from autode.utils import work_in_tmp_dir
+from autode.utils import work_in_tmp_dir, temporary_config
 from autode.atoms import Atom
 from autode.wrappers.XTB import XTB
 from autode.calculations import Calculation
@@ -216,6 +216,8 @@ def __init__(self):
             implicit_solvation_type=None,
             keywords_set=XTB().keywords,
         )
+        self.electronic_temp = XTB().electronic_temp
+        self.gfn_version = XTB().gfn_version
 
     def _energy_from(self, calc: "CalculationExecutor") -> PotentialEnergy:
         return XTB._energy_from(self, calc)
@@ -387,3 +389,32 @@ def test_xtb_cartesian_constrained_opt():
     # if the coordinates are constrained then the distance should be
     # close to the initial
     assert abs(h2.distance(0, 1) - init_r) < 0.1
+
+
+@pytest.mark.parametrize("gfn_ver,etemp", [(1, 300.0), (2, 1200.1)])
+@testutils.requires_with_working_xtb_install
+@work_in_tmp_dir()
+def test_xtb_etemp_and_gfn_var_params_recognised(gfn_ver, etemp):
+
+    # test that the electronic_temp and gfn_version Config params are recognised
+
+    mol = Molecule(smiles="O")
+    with temporary_config():
+        Config.XTB.gfn_version = gfn_ver
+        Config.XTB.electronic_temp = etemp
+
+        calc = Calculation(
+            name="water",
+            molecule=mol,
+            method=XTB(),
+            keywords=XTB().keywords.sp,
+        )
+        calc.run()
+
+    assert calc.output.filename is not None
+    output = "".join(calc.output.file_lines)
+
+    # xTB command line flags should be printed in the output
+    assert f"--gfn {gfn_ver}" in output
+    etemp_str = str(float(etemp))  # string repr may be different
+    assert f"--etemp {etemp_str}" in output