Пример #1
0
class NanoscaleStabilityTest(PymatgenTest):
    def setUp(self):

        # Load all entries
        La_hcp_entry_dict = get_entry_dict(
            os.path.join(get_path(""), "La_hcp_entries.txt"))
        La_fcc_entry_dict = get_entry_dict(
            os.path.join(get_path(""), "La_fcc_entries.txt"))
        with open(os.path.join(get_path(""),
                               'ucell_entries.txt')) as ucell_entries:
            ucell_entries = json.loads(ucell_entries.read())
        La_hcp_ucell_entry = ComputedStructureEntry.from_dict(
            ucell_entries["La_hcp"])
        La_fcc_ucell_entry = ComputedStructureEntry.from_dict(
            ucell_entries["La_fcc"])

        # Set up the NanoscaleStabilityClass
        self.La_hcp_analyzer = SurfaceEnergyPlotter(La_hcp_entry_dict,
                                                    La_hcp_ucell_entry)
        self.La_fcc_analyzer = SurfaceEnergyPlotter(La_fcc_entry_dict,
                                                    La_fcc_ucell_entry)
        self.nanoscale_stability = NanoscaleStability(
            [self.La_fcc_analyzer, self.La_hcp_analyzer])

    def test_stability_at_r(self):

        # Check that we have a different polymorph that is
        # stable below or above the equilibrium particle size
        r = self.nanoscale_stability.solve_equilibrium_point(
            self.La_hcp_analyzer, self.La_fcc_analyzer) * 10

        # hcp phase of La particle should be the stable
        # polymorph above the equilibrium radius
        hcp_wulff = self.La_hcp_analyzer.wulff_from_chempot()
        bulk = self.La_hcp_analyzer.ucell_entry
        ghcp, rhcp = self.nanoscale_stability.wulff_gform_and_r(
            hcp_wulff, bulk, r + 10, from_sphere_area=True)
        fcc_wulff = self.La_fcc_analyzer.wulff_from_chempot()
        bulk = self.La_fcc_analyzer.ucell_entry
        gfcc, rfcc = self.nanoscale_stability.wulff_gform_and_r(
            fcc_wulff, bulk, r + 10, from_sphere_area=True)
        self.assertGreater(gfcc, ghcp)

        # fcc phase of La particle should be the stable
        # polymorph below the equilibrium radius
        hcp_wulff = self.La_hcp_analyzer.wulff_from_chempot()
        bulk = self.La_hcp_analyzer.ucell_entry
        ghcp, rhcp = self.nanoscale_stability.wulff_gform_and_r(
            hcp_wulff, bulk, r - 10, from_sphere_area=True)
        fcc_wulff = self.La_fcc_analyzer.wulff_from_chempot()
        bulk = self.La_fcc_analyzer.ucell_entry
        gfcc, rfcc = self.nanoscale_stability.wulff_gform_and_r(
            fcc_wulff, bulk, r - 10, from_sphere_area=True)
        self.assertLess(gfcc, ghcp)
Пример #2
0
class NanoscaleStabilityTest(PymatgenTest):

    def setUp(self):

        # Load all entries
        La_hcp_entry_dict = get_entry_dict(os.path.join(get_path(""),
                                                        "La_hcp_entries.txt"))
        La_fcc_entry_dict = get_entry_dict(os.path.join(get_path(""),
                                                        "La_fcc_entries.txt"))
        with open(os.path.join(get_path(""), 'ucell_entries.txt')) as ucell_entries:
            ucell_entries = json.loads(ucell_entries.read())
        La_hcp_ucell_entry = ComputedStructureEntry.from_dict(ucell_entries["La_hcp"])
        La_fcc_ucell_entry = ComputedStructureEntry.from_dict(ucell_entries["La_fcc"])

        # Set up the NanoscaleStabilityClass
        self.La_hcp_analyzer = SurfaceEnergyPlotter(La_hcp_entry_dict,
                                                    La_hcp_ucell_entry)
        self.La_fcc_analyzer = SurfaceEnergyPlotter(La_fcc_entry_dict,
                                                    La_fcc_ucell_entry)
        self.nanoscale_stability = NanoscaleStability([self.La_fcc_analyzer,
                                                       self.La_hcp_analyzer])

    def test_stability_at_r(self):

        # Check that we have a different polymorph that is
        # stable below or above the equilibrium particle size
        r = self.nanoscale_stability.solve_equilibrium_point(self.La_hcp_analyzer,
                                                             self.La_fcc_analyzer)*10

        # hcp phase of La particle should be the stable
        # polymorph above the equilibrium radius
        hcp_wulff = self.La_hcp_analyzer.wulff_from_chempot()
        bulk = self.La_hcp_analyzer.ucell_entry
        ghcp, rhcp = self.nanoscale_stability.wulff_gform_and_r(hcp_wulff, bulk, r+10,
                                                                from_sphere_area=True)
        fcc_wulff = self.La_fcc_analyzer.wulff_from_chempot()
        bulk = self.La_fcc_analyzer.ucell_entry
        gfcc, rfcc = self.nanoscale_stability.wulff_gform_and_r(fcc_wulff, bulk, r+10,
                                                                from_sphere_area=True)
        self.assertGreater(gfcc, ghcp)

        # fcc phase of La particle should be the stable
        # polymorph below the equilibrium radius
        hcp_wulff = self.La_hcp_analyzer.wulff_from_chempot()
        bulk = self.La_hcp_analyzer.ucell_entry
        ghcp, rhcp = self.nanoscale_stability.wulff_gform_and_r(hcp_wulff, bulk, r-10,
                                                                from_sphere_area=True)
        fcc_wulff = self.La_fcc_analyzer.wulff_from_chempot()
        bulk = self.La_fcc_analyzer.ucell_entry
        gfcc, rfcc = self.nanoscale_stability.wulff_gform_and_r(fcc_wulff, bulk, r-10,
                                                                from_sphere_area=True)
        self.assertLess(gfcc, ghcp)
    def setUp(self):
        # Load all entries
        La_hcp_entry_dict = get_entry_dict(os.path.join(get_path(""), "La_hcp_entries.txt"))
        La_fcc_entry_dict = get_entry_dict(os.path.join(get_path(""), "La_fcc_entries.txt"))
        with open(os.path.join(get_path(""), "ucell_entries.txt")) as ucell_entries:
            ucell_entries = json.loads(ucell_entries.read())
        La_hcp_ucell_entry = ComputedStructureEntry.from_dict(ucell_entries["La_hcp"])
        La_fcc_ucell_entry = ComputedStructureEntry.from_dict(ucell_entries["La_fcc"])

        # Set up the NanoscaleStabilityClass
        self.La_hcp_analyzer = SurfaceEnergyPlotter(La_hcp_entry_dict, La_hcp_ucell_entry)
        self.La_fcc_analyzer = SurfaceEnergyPlotter(La_fcc_entry_dict, La_fcc_ucell_entry)
        self.nanoscale_stability = NanoscaleStability([self.La_fcc_analyzer, self.La_hcp_analyzer])
Пример #4
0
    def setUp(self):

        # Load all entries
        La_hcp_entry_dict = get_entry_dict(os.path.join(get_path(""),
                                                        "La_hcp_entries.txt"))
        La_fcc_entry_dict = get_entry_dict(os.path.join(get_path(""),
                                                        "La_fcc_entries.txt"))
        with open(os.path.join(get_path(""), 'ucell_entries.txt')) as ucell_entries:
            ucell_entries = json.loads(ucell_entries.read())
        La_hcp_ucell_entry = ComputedStructureEntry.from_dict(ucell_entries["La_hcp"])
        La_fcc_ucell_entry = ComputedStructureEntry.from_dict(ucell_entries["La_fcc"])

        # Set up the NanoscaleStabilityClass
        self.La_hcp_analyzer = SurfaceEnergyPlotter(La_hcp_entry_dict,
                                                    La_hcp_ucell_entry)
        self.La_fcc_analyzer = SurfaceEnergyPlotter(La_fcc_entry_dict,
                                                    La_fcc_ucell_entry)
        self.nanoscale_stability = NanoscaleStability([self.La_fcc_analyzer,
                                                       self.La_hcp_analyzer])