Exemplo n.º 1
0
            mat2d.lattice.matrix[0, :], mat2d.lattice.matrix[1, :],
            substrate.lattice.matrix[2, :]
        ]))
    substrate.modify_lattice(lmap)

    # put the 2d material on top of the substrate
    # seperation between the 2dmaterial and the substrate in angstroms
    seperation = 5
    substrate_top_z = np.max(
        np.array([site.coords for site in substrate])[:, 2])
    # shift origin and vector
    shift = substrate.lattice.matrix[2, :]
    shift = shift / np.linalg.norm(shift) * seperation
    origin = np.array([0, 0, substrate_top_z])
    for site in mat2d:
        new_coords = site.coords - origin + shift
        substrate.append(site.specie, new_coords, coords_are_cartesian=True)

    substrate.to(fmt='poscar', filename='POSCAR_final.vasp')

    # structure from materials project, use your own key
    # gaas = get_struct_from_mp('GaAs', MAPI_KEY="")
    # sa_gaas = SpacegroupAnalyzer(gaas)
    # gaas_cvn = sa_gaas.get_conventional_standard_structure()
    # gaas_cvn.to(fmt='poscar', filename='POSCAR_GaAs.vasp')

    # cdte = get_struct_from_mp('CdTe', MAPI_KEY="")
    # sa_cdte = SpacegroupAnalyzer(cdte)
    # cdte_cvn = sa_cdte.get_conventional_standard_structure()
    # cdte_cvn.to(fmt='poscar', filename='POSCAR_CdTe.vasp')
Exemplo n.º 2
0
def get_grain_boundary_interface(structure=None, hkl_pair= {'hkl': [[1,0,0],[1,1,0]],\
                                 'thickness':[10,10]}, twist = 0, tilt = 0, separation=0):
    """
    Args:
        structure: pymatgen structure to create grain boundary in
        hkl_pair:  dict of {'hkl':thickness}
        twist:     twist in degrees
        tilt:      tilt in degrees
    """


    structure = get_struct_from_mp(structure, MAPI_KEY="")
    sa = SpacegroupAnalyzer(structure)
    structure_conventional = sa.get_conventional_standard_structure()
    structure = structure_conventional.copy()
    structure.sort()

    #creation of lower part of grain boundary
    lower= Interface(structure,\
    hkl = hkl_pair['hkl'][0],
    min_thick = hkl_pair['thickness'][0],
    min_vac = separation+hkl_pair['thickness'][1],
    primitive = False, from_ase = True, center_slab=False)

    lower.to(fmt="poscar", filename="POSCAR_lower.vasp")

    #creation of upper part of grain boundary
    upper= Interface(structure,\
    hkl = hkl_pair['hkl'][1],
    min_thick = hkl_pair['thickness'][1],
    min_vac = 0,
    primitive = False, from_ase = True)

    #find top atoms reference of lower part of gb
    substrate_top_z = np.max(np.array([site.coords for site in lower])[:,2])

    # define twist and tilt vectors
    twist_shift_normal = lower.lattice.matrix[2,:]/\
                         np.linalg.norm(lower.lattice.matrix[2,:])
    tilt_normal = upper.lattice.matrix[1,:]/\
                  np.linalg.norm(upper.lattice.matrix[2,:])

    #define twist operation SymmOp object
    twist_op = SymmOp.from_axis_angle_and_translation(axis= twist_shift_normal,\
                angle=twist, angle_in_radians=False,translation_vec=(0, 0, 0))
    #define tilt operation SymmOp object
    tilt_op = SymmOp.from_axis_angle_and_translation(axis= tilt_normal,\
                angle=tilt, angle_in_radians=False,translation_vec=(0, 0, 0))
    upper.apply_operation(twist_op)
    upper.to(fmt="poscar", filename="POSCAR_upper.vasp")
    upper.apply_operation(tilt_op)

    #define shift separation along twist vector normal to upper plane
    shift = -1*twist_shift_normal/np.linalg.norm(twist_shift_normal) * separation
    #define origin to shift w.r.t top of the lower grain 
    origin = np.array([0,0, substrate_top_z])
    #shift sites in upper 
    for site in upper:
        new_coords = site.coords - origin  +  shift
        lower.append(site.specie, new_coords, coords_are_cartesian=True)
    return lower 
Exemplo n.º 3
0
def get_grain_boundary_interface(structure=None, hkl_pair= {'hkl': [[1,0,0],[1,1,0]],\
                                 'thickness':[10,10]}, twist = 0, tilt = 0, separation=0):
    """
    Args:
        structure: pymatgen structure to create grain boundary in
        hkl_pair:  dict of {'hkl':thickness}
        twist:     twist in degrees
        tilt:      tilt in degrees
    """

    structure = get_struct_from_mp(structure, MAPI_KEY="")
    sa = SpacegroupAnalyzer(structure)
    structure_conventional = sa.get_conventional_standard_structure()
    structure = structure_conventional.copy()
    structure.sort()

    #creation of lower part of grain boundary
    lower= Interface(structure,\
    hkl = hkl_pair['hkl'][0],
    min_thick = hkl_pair['thickness'][0],
    min_vac = separation+hkl_pair['thickness'][1],
    primitive = False, from_ase = True, center_slab=False)

    lower.to(fmt="poscar", filename="POSCAR_lower.vasp")

    #creation of upper part of grain boundary
    upper= Interface(structure,\
    hkl = hkl_pair['hkl'][1],
    min_thick = hkl_pair['thickness'][1],
    min_vac = 0,
    primitive = False, from_ase = True)

    #find top atoms reference of lower part of gb
    substrate_top_z = np.max(np.array([site.coords for site in lower])[:, 2])

    # define twist and tilt vectors
    twist_shift_normal = lower.lattice.matrix[2,:]/\
                         np.linalg.norm(lower.lattice.matrix[2,:])
    tilt_normal = upper.lattice.matrix[1,:]/\
                  np.linalg.norm(upper.lattice.matrix[2,:])

    #define twist operation SymmOp object
    twist_op = SymmOp.from_axis_angle_and_translation(axis= twist_shift_normal,\
                angle=twist, angle_in_radians=False,translation_vec=(0, 0, 0))
    #define tilt operation SymmOp object
    tilt_op = SymmOp.from_axis_angle_and_translation(axis= tilt_normal,\
                angle=tilt, angle_in_radians=False,translation_vec=(0, 0, 0))
    upper.apply_operation(twist_op)
    upper.to(fmt="poscar", filename="POSCAR_upper.vasp")
    upper.apply_operation(tilt_op)

    #define shift separation along twist vector normal to upper plane
    shift = -1 * twist_shift_normal / np.linalg.norm(
        twist_shift_normal) * separation
    #define origin to shift w.r.t top of the lower grain
    origin = np.array([0, 0, substrate_top_z])
    #shift sites in upper
    for site in upper:
        new_coords = site.coords - origin + shift
        lower.append(site.specie, new_coords, coords_are_cartesian=True)
    return lower
          mat2d.lattice.matrix[1,:],
          substrate.lattice.matrix[2,:]
        ] ) )    
    substrate.modify_lattice(lmap)

    # put the 2d material on top of the substrate
    # seperation between the 2dmaterial and the substrate in angstroms    
    seperation = 5
    substrate_top_z = np.max(np.array([site.coords for site in substrate])[:,2])
    # shift origin and vector
    shift = substrate.lattice.matrix[2,:]
    shift = shift/np.linalg.norm(shift) * seperation
    origin = np.array([0,0, substrate_top_z])    
    for site in mat2d:
        new_coords = site.coords - origin  +  shift
        substrate.append(site.specie, new_coords, coords_are_cartesian=True)

    substrate.to(fmt='poscar', filename='POSCAR_final.vasp')        
    

    #structure from materials project, use your own key
    #gaas = get_struct_from_mp('GaAs', MAPI_KEY="")
    #sa_gaas = SpacegroupAnalyzer(gaas)
    #gaas_cvn = sa_gaas.get_conventional_standard_structure()
    #gaas_cvn.to(fmt='poscar', filename='POSCAR_GaAs.vasp')
    
    #cdte = get_struct_from_mp('CdTe', MAPI_KEY="")
    #sa_cdte = SpacegroupAnalyzer(cdte)
    #cdte_cvn = sa_cdte.get_conventional_standard_structure()
    #cdte_cvn.to(fmt='poscar', filename='POSCAR_CdTe.vasp')