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   "source": [
    "## Using OpenKIM models with ASE\n",
    "\n",
    "This example demonstrates using an OpenKIM model installed on your system for an ASE calculation, specifically a static energy calculation of FCC Aluminum using the famous 1994 Ercolessi-Adams EAM potential. The [KIM query](https://openkim.org/doc/usage/kim-query/) Python module is used to obtain the lattice constant used for the simulation."
   ]
  },
  {
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   "source": [
    "This is what the calculation would look like without OpenKIM. The user is required to specify the lattice constant and obtain their own parameter file:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from ase.calculators.eam import EAM\n",
    "from ase.lattice.cubic import FaceCenteredCubic\n",
    "# Define the user-obtained parameter file and lattice constant\n",
    "model = \"potentials/v2_18_Al3Sm_2016.eam.fs\"\n",
    "calc = EAM(potential=model)\n",
    "a0 = 4.05\n",
    "# Set up fcc crystal\n",
    "atoms = FaceCenteredCubic(\"Al\", latticeconstant=a0)\n",
    "atoms.calc = calc\n",
    "# Compute energy and stress\n",
    "print(\"\\nPotential energy:\")\n",
    "print(atoms.get_potential_energy())"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Below is the same calculation using OpenKIM. The kim_query Python module is used to automatically obtain the lattice constant."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "from ase.calculators.kim import KIM\n",
    "from ase.lattice.cubic import FaceCenteredCubic\n",
    "from kim_query import get_lattice_constant_cubic\n",
    "# Define KIM model and get Al fcc lattice parameter for this potential\n",
    "model = \"EAM_Dynamo_SongMendelev_2021_AlSm__MO_722733117926_000\"\n",
    "calc = KIM(model)\n",
    "a0 = get_lattice_constant_cubic([model], [\"fcc\"], [\"Al\"], [\"angstrom\"])[0]\n",
    "# Set up fcc crystal\n",
    "atoms = FaceCenteredCubic(\"Al\", latticeconstant=a0)\n",
    "atoms.calc = calc\n",
    "# Compute energy and stress\n",
    "print(\"\\nPotential energy:\")\n",
    "print(atoms.get_potential_energy())"
   ]
  },
  {
   "attachments": {},
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   "metadata": {},
   "source": [
    "The energy is nearly identical, but slightly lower due to the lattice constant being the perfect equilibrium value. See the [KIM calculator in ASE documentation](https://wiki.fysik.dtu.dk/ase/ase/calculators/kim.html) for more info."
   ]
  }
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