Exemplo n.º 1
0
def pure_phase_entropy(small_bc):
    from cemc.mcmc import Montecarlo
    from ase.clease.tools import wrap_and_sort_by_position
    from ase.io import read
    from cemc.mcmc import SiteOrderParameter, Snapshot
    import dataset
    T = [1, 5, 10, 20, 30, 40, 50, 75, 100, 150, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 
         320, 330, 340, 350, 360, 370, 380, 390, 400, 420, 440, 460, 480, 500]
    calc = get_ce_calc(small_bc, kwargs, ecis, size=[10, 10, 10], db_name="data/db10x10x10Al3Mg.db")
    bc = calc.BC
    bc.atoms.set_calculator(calc)
    atoms = read("data/al3mg_template.xyz")
    atoms = wrap_and_sort_by_position(atoms)
    symbs = [atom.symbol for atom in atoms]
    calc.set_symbols(symbs)
    
    site_order = SiteOrderParameter(bc.atoms)
    db = dataset.connect("sqlite:///data/pure_al3mg3.db")
    syst = db["thermodynamic"]
    camera = Snapshot(trajfile="data/pure_phase_entropy.traj", atoms=bc.atoms)
    for temp in T:
        print("Current temperature: {}K".format(temp))
        site_order.reset()
        mc = Montecarlo(bc.atoms, temp)
        mc.attach(site_order)
        mc.attach(camera, interval=50000)
        equil_param = {"window_length": 100000, "mode": "fixed"}
        mc.runMC(mode="fixed", steps=500000, equil=True, equil_params=equil_param)
        mean, stddev = site_order.get_average()
        thermo = mc.get_thermodynamic()
        thermo["site_order"] = mean
        thermo["site_order_std"] = stddev
        syst.insert(thermo)
Exemplo n.º 2
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def sa(al_comp, kwargs, eci, db_name, size, lattice):
    comp = {"Al": al_comp, "Zn": 1.0 - al_comp}

    bc = BulkCrystal(**kwargs)
    calc = get_ce_calc(bc, kwargs, eci, size)
    bc = calc.BC
    bc.atoms.set_calculator(calc)
    temperatures = [800, 700, 600, 500, 400, 300, 200, 100]
    N = len(bc.atoms)

    if rank == 0:
        print("Supercell has {} atoms".format(N))

    # Define parameters for equillibration
    equil_params = {"maxiter": 10 * N, "mode": "fixed"}

    nsteps = 100 * N
    calc.set_composition(comp)
    for T in temperatures:
        mc = Montecarlo(bc.atoms, T, mpicomm=comm)
        mc.runMC(mode="fixed", steps=nsteps, equil_params=equil_params)
        thermo = mc.get_thermodynamic()
        thermo["converged"] = True
        thermo["al_conc"] = al_comp
        thermo["temperature"] = T
        if rank == 0:
            db = dataset.connect("sqlite:///{}".format(db_name))
            tbl = db["results"]
            tbl.insert(thermo)

    if rank == 0:
        fname = "data/atoms_{}_{}.xyz".format(lattice,
                                              bc.atoms.get_chemical_formula())
        write(fname, bc.atoms)
Exemplo n.º 3
0
    def insert_atoms( self, bc_kwargs, size=[1,1,1], composition=None, cetype="CEBulk", \
                      T=None, n_steps_per_temp=10000, eci=None ):
        """
        Insert a new atoms object into the database
        """
        if (composition is None):
            raise TypeError("No composition given")
        allowed_ce_types = ["CEBulk", "CECrystal"]
        if (not cetype in allowed_ce_types):
            raise ValueError(
                "cetype has to be one of {}".format(allowed_ce_types))
        self.cetype = cetype

        if (eci is None):
            raise ValueError(
                "No ECIs given! Cannot determine required energy range!")

        if (cetype == "CEBulk"):
            small_bc = CEBulk(**bc_kwargs)
            small_bc.reconfigure_settings()
        elif (ctype == "CECrystal"):
            small_bc = CECrystal(**bc_kwargs)
            small_bc.reconfigure_settings()

        self._check_eci(small_bc, eci)

        calc = get_ce_calc(small_bc, bc_kwargs, eci=eci, size=size)
        calc.set_composition(composition)
        bc = calc.BC
        bc.atoms.set_calculator(calc)

        formula = bc.atoms.get_chemical_formula()
        if (self.template_atoms_exists(formula)):
            raise AtomExistsError(
                "An atom object with the specified composition already exists in the database"
            )

        Emin, Emax = self._find_energy_range(bc.atoms, T, n_steps_per_temp)
        cf = calc.get_cf()
        data = {"cf": cf}
        # Store this entry into the database
        db = connect(self.wl_db_name)
        scalc = SinglePointCalculator(bc.atoms, energy=Emin)
        bc.atoms.set_calculator(scalc)

        outfname = "BC_wanglandau_{}.pkl".format(
            bc.atoms.get_chemical_formula())
        with open(outfname, 'wb') as outfile:
            pck.dump(bc, outfile)

        kvp = {
            "Emin": Emin,
            "Emax": Emax,
            "bcfile": outfname,
            "cetype": self.cetype
        }
        data["bc_kwargs"] = bc_kwargs
        data["supercell_size"] = size
        db.write(calc.BC.atoms, key_value_pairs=kvp, data=data)
Exemplo n.º 4
0
def sa_sgc():
    alat = 3.8
    conc_args = {}
    conc_args['conc_ratio_min_1'] = [[1, 0]]
    conc_args['conc_ratio_max_1'] = [[0, 1]]
    kwargs = {
        "crystalstructure": 'fcc',
        "a": 3.8,
        "size": [10, 10, 10],
        # "size": [2, 2, 2],
        "basis_elements": [['Cu', 'Au']],
        "conc_args": conc_args,
        "db_name": 'temp_sgc{}.db'.format(rank),
        "max_cluster_size": 3,
        "max_cluster_dist": 1.5 * alat
    }
    with open("data/eci_aucu.json", 'r') as infile:
        eci = json.load(infile)
    bc = BulkCrystal(**kwargs)
    bc.reconfigure_settings()
    with open("data/eci_aucu.json", 'r') as infile:
        eci = json.load(infile)
    calc = get_ce_calc(bc, kwargs, eci=eci, size=[10, 10, 10])
    bc = calc.BC
    bc.atoms.set_calculator(calc)
    atoms = bc.atoms

    chem_pot = (np.linspace(0.19, 0.35, 50)).tolist()
    T = np.linspace(100, 1000, 50)[::-1]
    equil_param = {"mode": "fixed", "maxiter": 10 * len(atoms)}
    nsteps = 100 * len(atoms)

    sgc_db = dataset.connect("sqlite:///{}".format(sgc_db_name))
    tbl = sgc_db["results"]
    tbl_cf = sgc_db["corr_func"]
    orig_symbs = [atom.symbol for atom in atoms]
    for mu in chem_pot:
        chemical_potential = {"c1_0": mu}
        calc.set_symbols(orig_symbs)
        for temp in T:
            mc = SGCMonteCarlo(atoms, temp, mpicomm=comm, symbols=["Au", "Cu"])
            init_formula = atoms.get_chemical_formula()
            mc.runMC(steps=nsteps,
                     equil_params=equil_param,
                     chem_potential=chemical_potential)
            thermo = mc.get_thermodynamic(reset_ecis=True)
            thermo["init_formula"] = init_formula
            thermo["final_formula"] = atoms.get_chemical_formula()
            if rank == 0:
                uid = tbl.insert(thermo)
                cf = calc.get_cf()
                cf["runID"] = uid
                tbl_cf.insert(cf)
Exemplo n.º 5
0
def main(size, T):
    atoms = create_surface(size)
    atoms = wrap_and_sort_by_position(atoms)
    conc_args = {
        "conc_ratio_min_1": [[64, 0, 0]],
        "conc_ratio_max_1": [[24, 40, 0]],
        "conc_ratio_min_2": [[64, 0, 0]],
        "conc_ratio_max_2": [[22, 21, 21]]
    }

    kwargs = {
        "crystalstructure": "fcc",
        "a": 4.05,
        "size": [4, 4, 4],
        "basis_elements": [["Al", "Mg", "Si"]],
        "conc_args": conc_args,
        "db_name": "data/almgsi.db",
        "max_cluster_size": 4
    }

    ceBulk = BulkCrystal(**kwargs)
    eci_file = "data/almgsi_fcc_eci_newconfig.json"
    with open(eci_file, 'r') as infile:
        ecis = json.load(infile)
    db_name = "large_cell_db{}x{}x{}.db".format(size[0], size[1], size[2])
    calc = get_ce_calc(ceBulk, kwargs, ecis, size=size, db_name=db_name)
    ceBulk = calc.BC
    ceBulk.atoms.set_calculator(calc)

    mc = Montecarlo(ceBulk.atoms, T)
    symbs = [atom.symbol for atom in atoms]
    mc.set_symbols(symbs)

    # Write a copy of the current atoms object
    from ase.io import write
    shape_str = "-".join((str(item) for item in size))
    uid_str = "{}K_{}".format(T, shape_str)
    write(WORKDIR + "initial_config{}.xyz".format(uid_str), mc.atoms)

    backup = MCBackup(mc,
                      backup_file=WORKDIR + "backup{}.xyz".format(uid_str),
                      db_name=WORKDIR + "mc_surface.db")
    camera = Snapshot(atoms=mc.atoms,
                      trajfile=WORKDIR + "surface{}.traj".format(uid_str))
    evol = EnergyEvolution(mc)
    nsteps = int(10E6)
    mc.attach(backup, interval=100000)
    mc.attach(camera, interval=int(nsteps / 20))
    mc.attach(evol, interval=10 * len(mc.atoms))
    mc.runMC(mode="fixed", steps=nsteps, equil=False)
    write(WORKDIR + "final_config{}.xyz".format(uid_str), mc.atoms)
Exemplo n.º 6
0
    def test_no_throw(self):
        if (not has_CE):
            self.skipTest("ASE version does not have ASE")
            return
        no_throw = True
        msg = ""
        try:
            conc_args = {
                "conc_ratio_min_1": [[1, 0]],
                "conc_ratio_max_1": [[0, 1]],
            }
            kwargs = {
                "crystalstructure": "fcc",
                "a": 4.05,
                "size": [3, 3, 3],
                "basis_elements": [["Al", "Mg"]],
                "conc_args": conc_args,
                "db_name": "temporary_bcnucleationdb.db",
                "max_cluster_size": 3
            }
            ceBulk = CEBulk(**kwargs)
            cf = CorrFunction(ceBulk)
            cf_dict = cf.get_cf(ceBulk.atoms)
            ecis = {key: 1.0 for key, value in cf_dict.items()}

            #calc = CE( ceBulk, ecis, size=(3,3,3) )
            calc = get_ce_calc(ceBulk,
                               kwargs,
                               ecis,
                               size=[6, 6, 6],
                               db_name="sc6x6x6.db")
            ceBulk = calc.BC
            ceBulk.atoms.set_calculator(calc)
            chem_pot = {"c1_0": -1.069}

            T = 300
            mc = SGCFreeEnergyBarrier( ceBulk.atoms, T, symbols=["Al","Mg"], \
            n_windows=5, n_bins=10, min_singlet=0.5, max_singlet=1.0 )
            mc.run(nsteps=100, chem_pot=chem_pot)
            mc.save(fname="free_energy_barrier.json")

            # Try to load the object stored
            mc = SGCFreeEnergyBarrier.load(ceBulk.atoms,
                                           "free_energy_barrier.json")
            mc.run(nsteps=100, chem_pot=chem_pot)
            mc.save(fname="free_energy_barrier.json")
            os.remove("sc6x6x6.db")
        except Exception as exc:
            msg = str(exc)
            no_throw = False
        self.assertTrue(no_throw, msg=msg)
Exemplo n.º 7
0
def insert_energy(conc, T):
    alat = 3.8
    conc_args = {}
    conc_args['conc_ratio_min_1'] = [[1, 0]]
    conc_args['conc_ratio_max_1'] = [[0, 1]]
    kwargs = {
        "crystalstructure": 'fcc',
        "a": 3.8,
        "size": [4, 4, 2],
        "basis_elements": [['Cu', 'Au']],
        "conc_args": conc_args,
        "db_name": 'temp_sgc{}.db'.format(rank),
        "max_cluster_size": 3,
        "max_cluster_dist": 1.5 * alat
    }
    bc = BulkCrystal(**kwargs)
    bc.reconfigure_settings()

    with open("data/eci_aucu.json", 'r') as infile:
        eci = json.load(infile)

    names = bc.cluster_names
    for key in eci.keys():
        if key not in names:
            raise ValueError("{} is not in cluster_names".format(key))
    calc = get_ce_calc(bc, kwargs, eci=eci, size=[10, 10, 10])
    bc = calc.BC
    atoms = bc.atoms
    atoms.set_calculator(calc)

    comp = {"Au": conc, "Cu": 1.0 - conc}
    calc.set_composition(comp)
    symbs = [atom.symbol for atom in atoms]
    shuffle(symbs)
    calc.set_symbols(symbs)

    sampler = ActivitySampler(atoms,
                              T,
                              moves=[("Au", "Cu")],
                              mpicomm=comm,
                              prob_insert_move=0.1)
    equil = {"mode": "fixed", "maxiter": 10 * len(atoms)}
    nsteps = 100 * len(atoms)
    sampler.runMC(steps=nsteps, mode="fixed", equil_params=equil)

    thermo = sampler.get_thermodynamic()
    if rank == 0:
        db = dataset.connect("sqlite:///{}".format(db_name))
        tbl = db["results"]
        tbl.insert(thermo)
Exemplo n.º 8
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    def test_supercell( self ):
        if ( not has_ase_with_ce ):
            self.skipTest("ASE version does not have CE")
            return

        calc, ceBulk, eci = self.get_calc("fcc")
        db_name = "test_db_fcc_super.db"

        conc_args = {
            "conc_ratio_min_1":[[1,0]],
            "conc_ratio_max_1":[[0,1]],
        }

        kwargs = {
            "crystalstructure": "fcc",
            "a": 4.05,
            "size":[3, 3, 3],
            "basis_elements":[["Al","Mg"]],
            "conc_args": conc_args,
            "db_name": db_name,
            "max_cluster_size": 3,
            "max_cluster_dia": 4.05
        }

        kwargs_template = copy.deepcopy(kwargs)
        kwargs_template["size"] = [4, 4, 4]
        kwargs_template["db_name"] = "template_bc.db"
        template_supercell_bc = CEBulk(**kwargs_template)
        template_supercell_bc.reconfigure_settings()

        ceBulk = CEBulk(**kwargs)
        ceBulk.reconfigure_settings()
        calc = get_ce_calc(ceBulk, kwargs, eci, size=[4, 4, 4],
                           db_name="sc4x4x.db")
        ceBulk = calc.BC
        ceBulk.atoms.set_calculator(calc)
        corr_func = CorrFunction(template_supercell_bc)
        for i in range(10):
            calc.calculate(ceBulk.atoms, ["energy"], [(i, "Al", "Mg")])
            updated_cf = calc.get_cf()
            brute_force = corr_func.get_cf_by_cluster_names(
                ceBulk.atoms, list(updated_cf.keys()))

            for key, value in brute_force.items():
                self.assertAlmostEqual(value, updated_cf[key])
        os.remove("sc4x4x.db")
Exemplo n.º 9
0
def run_huge():
    conc_args = {
        "conc_ratio_min_1":[[64,0,0]],
        "conc_ratio_max_1":[[24,40,0]],
        "conc_ratio_min_2":[[64,0,0]],
        "conc_ratio_max_2":[[22,21,21]]
    }

    kwargs = {
        "crystalstructure":"fcc",
        "size":[4,4,4],
        "basis_elements":[["Al","Mg","Si"]],
        "conc_args":conc_args,
        "db_name":"some_db.db",
        "max_cluster_size":4,
        "a":4.05,
        "ce_init_alg":"fast"
    }
    ceBulk = BulkCrystal( **kwargs )

    with open(eci_file, 'r') as infile:
        eci = json.load(infile)
    calc = get_ce_calc(ceBulk, kwargs, eci=eci, size=[50,50,50])
    calc.BC.atoms.set_calculator(calc)
    print(calc.BC.basis_functions)

    comp = {
        "Al":0.9,
        "Mg":0.05,
        "Si":0.05
    }
    calc.set_composition(comp)

    T = 150
    T = [2000, 1500, 1200, 1000, 800, 600, 400, 293]
    camera = Snapshot(trajfile=traj_file, atoms=calc.BC.atoms)
    for temp in T:
        print("Current temperature {}K".format(temp))
        mc = Montecarlo(calc.BC.atoms, temp)
        mc.attach(camera, interval=125000*20)
        mc.runMC(mode="fixed", steps=125000*100, equil=False)
Exemplo n.º 10
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    def get_atoms(self, atomID, eci):
        """
        Returns an instance of the atoms object requested
        """
        db = connect(self.wl_db_name)
        row = db.get(id=atomID)
        bcfname = row.key_value_pairs["bcfile"]
        init_cf = row.data["cf"]
        try:
            with open(bcfname, 'rb') as infile:
                bc = pck.load(infile)
            calc = CE(bc, eci, initial_cf=init_cf)
            bc.atoms.set_calculator(calc)
            return bc.atoms
        except IOError as exc:
            print(str(exc))
            print("Will try to recover the CEBulk object")
            bc_kwargs = row.data["bc_kwargs"]
            cetype = row.key_value_pairs["cetype"]
            if (cetype == "CEBulk"):
                small_bc = CEBulk(**bc_kwargs)
                small_bc.reconfigure_settings()
            else:
                small_bc = CECrystal(**bc_kwargs)
                small_bc.reconfigure_settings()
            size = row.data["supercell_size"]
            calc = get_ce_calc(small_bc, bc_kwargs, eci=eci, size=size)

            # Determine the composition
            count = row.count_atoms()
            for key in count.keys():
                count /= float(row.natoms)
            calc.set_composition(count)
            bc = calc.BC
            bc.atoms.set_calculator(calc)
            return bc.atoms
        except:
            raise RuntimeError(
                "Did not manage to return the atoms object with the proper calculator attached..."
            )
def run(chem_pot, min_c1, max_c1, T):
    alat = 3.8
    conc_args = {}
    conc_args['conc_ratio_min_1'] = [[1, 0]]
    conc_args['conc_ratio_max_1'] = [[0, 1]]
    kwargs = {
        "crystalstructure": 'fcc',
        "a": 3.8,
        "size": [10, 10, 10],
        # "size": [2, 2, 2],
        "basis_elements": [['Cu', 'Au']],
        "conc_args": conc_args,
        "db_name": 'temp_sgc_{}.db'.format(rank),
        "max_cluster_size": 3,
        "max_cluster_dist": 1.5 * alat
    }
    bc = BulkCrystal(**kwargs)
    with open("data/eci_aucu.json", 'r') as infile:
        eci = json.load(infile)
    calc = get_ce_calc(bc, kwargs, eci=eci, size=[10, 10, 10])
    bc = calc.BC
    bc.atoms.set_calculator(calc)
    if rank == 0:
        print("Number of atoms: {}".format(len(bc.atoms)))

    mc = SGCFreeEnergyBarrier(bc.atoms,
                              T,
                              n_windows=10,
                              n_bins=8,
                              min_singlet=min_c1,
                              max_singlet=max_c1,
                              mpicomm=comm,
                              symbols=["Au", "Cu"],
                              save_last_state=True)
    mu = {"c1_0": chem_pot}
    mc.run(nsteps=100000, chem_pot=mu)
    # mc.save(fname="data/barriers/free_eng_{}_{}_{}_{}.json".format(int(min_c1*100), int(max_c1*100), int(1E6*chem_pot), T))
    mc.save(fname="data/barrier_sgc_waste4.json")
Exemplo n.º 12
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def get_ce_with_calc():
    conc = Concentration(basis_elements=[["Al", "Mg", "Si"]])
    kwargs = {
        "crystalstructure": "fcc",
        "a": 4.05,
        "size": [4, 4, 4],
        "concentration": conc,
        "db_name": DB_NAME,
        "max_cluster_size": 4
    }
    ceBulk = BulkCrystal(**kwargs)

    with open(ECI_FILE, 'r') as infile:
        ecis = json.load(infile)

    db_name = "large_cell_db10x10x10.db"
    calc = get_ce_calc(ceBulk,
                       kwargs,
                       ecis,
                       size=[10, 10, 10],
                       db_name=db_name)
    ceBulk = calc.BC
    ceBulk.atoms.set_calculator(calc)
    return ceBulk
Exemplo n.º 13
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def main(outfname, action):
    conc_args = {
        "conc_ratio_min_1": [[1, 0]],
        "conc_ratio_max_1": [[0, 1]],
    }
    kwargs = {
        "crystalstructure": "fcc",
        "a": 4.05,
        "size": [4, 4, 4],
        "basis_elements": [["Al", "Mg"]],
        "conc_args": conc_args,
        "db_name": "data/temporary_bcnucleationdb.db",
        "max_cluster_size": 4
    }
    ceBulk = BulkCrystal(**kwargs)
    print(ceBulk.basis_functions)

    eci_file = "data/ce_hydrostatic.json"
    with open(eci_file, 'r') as infile:
        ecis = json.load(infile)
    print(ecis)
    #calc = CE( ceBulk, ecis, size=(3,3,3) )
    ecis = {"c1_0": 1.0}
    calc = get_ce_calc(ceBulk,
                       kwargs,
                       ecis,
                       size=[10, 10, 10],
                       free_unused_arrays_BC=True,
                       convert_trans_matrix=False)
    exit()
    ceBulk = calc.BC
    ceBulk.atoms.set_calculator(calc)

    chem_pot = {"c1_0": -1.0651526881167124}
    chem_pot = {"c1_0": -1.068}
    sampler = NucleationSampler( size_window_width=10, \
    chemical_potential=chem_pot, max_cluster_size=150, \
    merge_strategy="normalize_overlap", mpicomm=comm, max_one_cluster=True )

    T = 300
    mc = SGCNucleation( ceBulk.atoms, T, nucleation_sampler=sampler, \
    network_name="c2_1414_1",  network_element="Mg", symbols=["Al","Mg"], \
    chem_pot=chem_pot, allow_solutes=True )

    mg_conc = 0.04
    concentration = {"Mg": mg_conc, "Al": 1.0 - mg_conc}

    mc_canonical = CanonicalNucleationMC(ceBulk.atoms,
                                         T,
                                         nucleation_sampler=sampler,
                                         network_name="c2_1414_1",
                                         network_element="Mg",
                                         concentration=concentration)

    if (action == "barrier"):
        mc.run(nsteps=100000)
        sampler.save(fname=outfname)
    elif (action == "barrier_canonical"):
        mc_canonical.run(nsteps=50000)
        sampler.save(fname=outfname)
    elif (action == "trans_path"):
        mc.find_transition_path( initial_cluster_size=90, max_size_reactant=20, min_size_product=135, \
        folder="data", path_length=1000, max_attempts=10, nsteps=int(0.1*len(ceBulk.atoms)), mpicomm=comm )
        #plt.show()
    elif (action == "relax_path"):
        relaxer = TransitionPathRelaxer(nuc_mc=mc)
        relaxer.relax_path(initial_path=outfname, n_shooting_moves=50)
        relaxer.path2trajectory(fname="data/relaxed_path.traj")
    elif (action == "generate_paths"):
        relaxer = TransitionPathRelaxer(nuc_mc=mc)
        relaxer.generate_paths(initial_path=outfname,
                               n_paths=4,
                               outfile="data/tse_ensemble.json",
                               mpicomm=comm)
    elif (action == "view_tps_indicators"):
        relaxer = TransitionPathRelaxer(nuc_mc=mc)
        relaxer.plot_path_statistics(path_file=outfname)
        plt.show()
def surface_energy():
    conc_args = {
        "conc_ratio_min_1": [[64, 0, 0]],
        "conc_ratio_max_1": [[24, 40, 0]],
        "conc_ratio_min_2": [[64, 0, 0]],
        "conc_ratio_max_2": [[22, 21, 21]]
    }

    kwargs = {
        "crystalstructure": "fcc",
        "a": 4.05,
        "size": [4, 4, 4],
        "basis_elements": [["Al", "Mg", "Si"]],
        "conc_args": conc_args,
        "db_name": "data/almgsi.db",
        "max_cluster_size": 4
    }

    ceBulk = CEBulk(**kwargs)
    eci_file = "data/almgsi_fcc_eci_newconfig.json"
    with open(eci_file, 'r') as infile:
        ecis = json.load(infile)
    size = (8, 8, 8)
    db_name = "large_cell_db{}x{}x{}.db".format(size[0], size[1], size[2])
    calc = get_ce_calc(ceBulk, kwargs, ecis, size=size, db_name=db_name)
    print(calc.get_energy() / len(calc.atoms))
    ceBulk = calc.BC
    ceBulk.atoms.set_calculator(calc)

    # Get the energy of MgSi
    mgsi = wrap_and_sort_by_position(get_mgsi() * (4, 4, 4))
    symbs = [atom.symbol for atom in mgsi]
    calc.set_symbols(symbs)
    view(calc.atoms)
    mgsi_energy = calc.get_energy() / len(calc.atoms)
    print("Energy MgSi: {} eV/atom".format(mgsi_energy))

    # Get the energy of pure al
    symbs = ["Al" for _ in range(len(mgsi))]
    calc.set_symbols(symbs)
    view(calc.atoms)
    al_energy = calc.get_energy() / len(calc.atoms)
    print("Energy Al: {} eV/atom".format(al_energy))

    # Get the energy of a 50% mixture
    mgsi = wrap_and_sort_by_position(get_mgsi() * (4, 4, 2))
    # mgsi = get_mgsi_surface100_si_si()
    from scipy.spatial import cKDTree as KDTree
    cell = calc.atoms.get_cell()
    tree = KDTree(calc.atoms.get_positions())
    symbs = [atom.symbol for atom in calc.atoms]
    for atom in mgsi:
        pos = np.zeros((1, 3))
        pos[0, :] = atom.position
        wrapped = wrap_positions(pos, cell)
        if not np.allclose(wrapped, atom.position):
            continue
        _, indx = tree.query(atom.position)
        symbs[indx] = atom.symbol
    calc.set_symbols(symbs)
    view(calc.atoms)

    # Surface energy
    mix_energy = calc.get_energy()
    print("Mix energy: {} eV ({} eV/atom)".format(mix_energy, mix_energy /
                                                  len(calc.atoms)))
    num_al = 0
    num_mgsi = 0
    for atom in calc.atoms:
        if atom.symbol == "Al":
            num_al += 1
        elif atom.symbol == "Mg" or atom.symbol == "Si":
            num_mgsi += 1
    assert num_al + num_mgsi == len(calc.atoms)
    dE = mix_energy - num_al * al_energy - num_mgsi * mgsi_energy
    cell = calc.atoms.get_cell()
    a1 = cell[0, :]
    a2 = cell[1, :]
    normal = np.cross(a1, a2)
    area = np.sqrt(normal.dot(normal))

    # Convert units
    surface_tension = dE / area
    mJ = J / 1000.0  # milli joules
    surface_tension *= (m * m / mJ)
    unit_normal = normal / area
    print("Surface tension: {} mJ/m^2".format(surface_tension))
    print("Direction: {}".format(unit_normal))
Exemplo n.º 15
0
    def test_no_throw(self):
        if not available:
            self.skipTest("ASE version does not have CE!")
            return
        no_throw = True
        msg = ""
        try:
            conc_args = {
                "conc_ratio_min_1": [[1, 0]],
                "conc_ratio_max_1": [[0, 1]],
            }
            db_name = "temp_nuc_db.db"
            if os.path.exists(db_name):
                os.remove(db_name)
            kwargs = {
                "crystalstructure": "fcc",
                "a": 4.05,
                "size": [3, 3, 3],
                "basis_elements": [["Al", "Mg"]],
                "conc_args": conc_args,
                "db_name": db_name,
                "max_cluster_size": 3
            }
            ceBulk = CEBulk(**kwargs)
            ceBulk.reconfigure_settings()
            cf = CorrFunction(ceBulk)
            cf = cf.get_cf(ceBulk.atoms)

            ecis = {key: 0.001 for key in cf.keys()}
            calc = get_ce_calc(ceBulk,
                               kwargs,
                               ecis,
                               size=[5, 5, 5],
                               db_name="sc5x5x5.db")
            ceBulk = calc.BC
            ceBulk.atoms.set_calculator(calc)

            chem_pot = {"c1_0": -1.0651526881167124}
            sampler = NucleationSampler(size_window_width=10,
                                        chemical_potential=chem_pot,
                                        max_cluster_size=20,
                                        merge_strategy="normalize_overlap")

            nn_name = get_network_name(ceBulk.cluster_family_names_by_size)

            mc = SGCNucleation(ceBulk.atoms,
                               300,
                               nucleation_sampler=sampler,
                               network_name=[nn_name],
                               network_element=["Mg"],
                               symbols=["Al", "Mg"],
                               chem_pot=chem_pot)

            mc.runMC(steps=2)
            sampler.save(fname="test_nucl.h5")

            mc = CanonicalNucleationMC(ceBulk.atoms,
                                       300,
                                       nucleation_sampler=sampler,
                                       network_name=[nn_name],
                                       network_element=["Mg"],
                                       concentration={
                                           "Al": 0.8,
                                           "Mg": 0.2
                                       })
            mc.runMC(steps=2)
            sampler.save(fname="test_nucl_canonical.h5")
            elements = {"Mg": 6}
            calc.set_composition({"Al": 1.0, "Mg": 0.0})
            mc = FixedNucleusMC(ceBulk.atoms,
                                300,
                                network_name=[nn_name],
                                network_element=["Mg"])
            mc.insert_symbol_random_places("Mg", num=1, swap_symbs=["Al"])
            mc.runMC(steps=2, elements=elements)
            os.remove("sc5x5x5.db")
        except Exception as exc:
            msg = str(exc)
            no_throw = False
        self.assertTrue(no_throw, msg=msg)
Exemplo n.º 16
0
def main(option="relax", size=8):
    from copy import deepcopy
    ceBulk = BulkCrystal( **kwargs )
    bc_copy = deepcopy(ceBulk)

    print (ecis)
    al,mg = get_pure_energies(ecis)
    print ("Al energy: {} eV/atom".format(al))
    print ("Mg energy: {} eV/atom".format(mg))
    #exit()
    #calc = CE( ceBulk, ecis, size=(3,3,3) )
    calc = get_ce_calc(ceBulk, kwargs, ecis, size=[15,15,15])
    ceBulk = calc.BC
    ceBulk.atoms.set_calculator( calc )
    #pure_energy = calc.get_energy()
    #print (pure_energy)
    #energy = calc.calculate( ceBulk.atoms, ["energy"],[(0,"Al","Mg")])
    #print (energy)
    #energy = calc.calculate( ceBulk.atoms, ["energy"], [()])
    #exit()

    if option == "heat":
        print("Running with cluser size {}".format(size))
        mc = FixedNucleusMC( ceBulk.atoms, 293, network_name=["c2_4p050_3"], network_element=["Mg"] )
        cluster_entropy(mc, size=size)
        return
    elif option == "pure_phase":
        pure_phase_entropy(bc_copy)
        return
    else:
        sizes = range(3,51)
        #sizes = np.arange(3, 51)
        energies = []
        cell = ceBulk.atoms.get_cell()
        diag = 0.5*(cell[0, :] + cell[1, :] + cell[2, :])
        pos = ceBulk.atoms.get_positions()
        pos -= diag
        lengths = np.sum(pos**2, axis=1)
        indx = np.argmin(lengths)
        symbs = [atom.symbol for atom in ceBulk.atoms]
        symbs[indx] = "Mg"
        print("Orig energy: {}".format(calc.get_energy()))
        calc.set_symbols(symbs)
        print("One atom: {}".format(calc.get_energy()))
        exit()

        for size in sizes:
            elements = {"Mg": size}
            T = np.linspace(50,1000,40)[::-1]

            # Reset the symbols to only Mg
            calc.set_symbols(symbs)
            mc = FixedNucleusMC( ceBulk.atoms, T, network_name=["c2_4p050_3"], network_element=["Mg"] )
            mc.grow_cluster(elements)
            mc.current_energy = calc.get_energy()
            low_en = LowestEnergyStructure( calc, mc, verbose=True )
            mc.attach( low_en )
            for temp in T:
                print ("Temperature {}K".format(temp))
                mc.T = temp
                mc.runMC(steps=10000, init_cluster=False)
                mc.reset()
                mc.is_first = False
            # atoms,clust = mc.get_atoms( atoms=low_en.atoms )
            write( "{}cluster{}_all.cif".format(folder,size), low_en.atoms )
            # write( "{}cluster{}_cluster.cif".format(folder,size), clust )
            energies.append(low_en.lowest_energy)
            print (sizes,energies)
        data = np.vstack((sizes,energies)).T
        np.savetxt( "{}energies_run2.txt".format(folder), data, delimiter=",")
Exemplo n.º 17
0
    "db_name": db_name,
    "conc_args": conc_args,
    "max_cluster_size": 3
}

# In this example, we just use some example ecis
eci = get_example_ecis(bc_kwargs=kwargs)

# Initialize a template CEBulk Object
ceBulk = CEBulk( **kwargs )
ceBulk.reconfigure_settings()  # Nessecary for the unittests to pass
# Now we want to get a Cluster Expansion calculator for a big cell
mc_cell_size = [10,10,10]
from cemc import get_ce_calc

calc = get_ce_calc( ceBulk, kwargs, eci=eci, size=mc_cell_size, db_name="mc_obs.db")
ceBulk = calc.BC
ceBulk.atoms.set_calculator(calc)

conc = {
    "Al":0.8,
    "Mg":0.2
}
calc.set_composition(conc)

# Now we import the Monte Carlo class
from cemc.mcmc.montecarlo import Montecarlo
T = 400 # Run the simulation at 400K
mc_obj = Montecarlo( ceBulk.atoms, T )

# Now we define the observers
Exemplo n.º 18
0
    "conc_args": conc_args,
    "max_cluster_size": 3
}

# Use some example ecis
eci = get_example_ecis(bc_kwargs=kwargs)

# Initialize a template CEBulk Object
ceBulk = CEBulk( **kwargs )
ceBulk.reconfigure_settings()  # Nessecary for the unittest to pass

# Now we want to get a Cluster Expansion calculator for a big cell
mc_cell_size = [10, 10, 10]
from cemc import get_ce_calc

calc = get_ce_calc(ceBulk, kwargs, eci=eci, size=mc_cell_size,
                   db_name="sgc_large.db")

# Now er are finished with the template CEBulk
ceBulk = calc.BC
ceBulk.atoms.set_calculator( calc )

# In the SGC ensemble the simulation is run at fixed chemical potential
# The chemical potentials are subtracted from the singlet terms
# Those are ECIs starting with c1.
# In a binary system there is only one singlet term, so there is only one
# chemical potential to specify
chem_pot = {
    "c1_0":-1.04
}

# Speciy the temperature