MWNTGenerator

class sknano.generators.MWNTGenerator(*args, from_scaling_matrix=False, **kwargs)

Bases: sknano.generators.NanotubeBundleGeneratorBase, sknano.generators.MWNTGeneratorBase, sknano.core.structures.MWNT

Class for generating multi-walled nanotubes (MWNT).

Changed in version 0.4.0: MWNTGenerator now generates both single MWNTs and MWNT bundles.

New in version 0.2.8.

Parameters:

• Ch_list (list, optional) – (n, m) for each SWNT wall in MWNT.
• Nwalls (int, optional) – Number of SWNT walls in MWNT.
• Lz (float, optional) – MWNT length in Angstroms.
• min_wall_diameter (float, optional) – Minimum MWNT wall diameter, in units of Angstroms.
• max_wall_diameter (float, optional) – Maximum MWNT wall diameter, in units of Angstroms.
• max_walls (int, optional) – Maximum number of MWNT walls.
• chiral_types ({None, 'armchair', 'zigzag', 'achiral', 'chiral'}, optional) – If None, the chiral_type of each MWNT walls will be random and determined by the set of randomly selected chiral indices (n, m).
• wall_spacing (float, optional) – Inter-wall spacing in units of Angstroms. Default value is the van der Waals interaction distance of 3.4 Angstroms.
• ny (nx,) – Number of repeat unit cells in the \(x, y\) dimensions.
• vdw_radius (float, optional) – van der Waals radius of nanotube atoms
• basis ({list}, optional) –

  List of strs of element symbols or atomic number of the two atom basis (default: [‘C’, ‘C’])

  New in version 0.3.10.

• element2 (element1,) –

  Element symbol or atomic number of basis Atom 1 and 2

  Deprecated since version 0.3.10: Use basis instead

• bond (float, optional) – \(\mathrm{a}_{\mathrm{CC}} =\) distance between nearest neighbor atoms, in units of Angstroms.
• bundle_packing ({'hcp', 'ccp'}, optional) – Packing arrangement of MWNT bundles. If bundle_packing is None, then it will be determined by the bundle_geometry parameter if bundle_geometry is not None. If both bundle_packing and bundle_geometry are None, then bundle_packing defaults to hcp.
• bundle_geometry ({'triangle', 'hexagon', 'square', 'rectangle'}, optional) –
• autogen (bool, optional) – if True, automatically call generate.
• verbose (bool, optional) – if True, show verbose output

Examples

>>> from sknano.generators import MWNTGenerator
>>> MWNTGenerator(Nwalls=5, min_wall_diameter=10, Lz=50).save()

The above command generated a 5 wall, 50 Angstrom long MWNT. The only constraints on the MWNT wall chiralities were the diameter constraints imposed by the min_wall_diameter parameter, which set the minimum wall diameter to 10 Angstroms, as well as the minimum wall-to-wall separation, which defaults to the van der Waals distance of 3.4 Angstroms.

This MWNT chirality may be written as:

\(\mathbf{C}_{\mathrm{h}} = (8,7)@(17,8)@(9,24)@(27,18)@(22,32)\)

Here’s a colorful rendering of the generated MWNT structure:

In the next example, we generate a MWNT bundle.

>>> mwntbundle = MWNTGenerator(Nwalls=5, min_wall_diameter=5, Lz=50,
...                            bundle_geometry='hexagon')
>>> mwntbundle.save()

Attributes

Ch_list	List of chiralities.
Lx	Axis-aligned length along the x-axis in Angstroms.
Ly	Axis-aligned length along the y-axis in Angstroms.
Lz	MWNT length in Angstroms.
Lz_list	MWNT length \(L_z = L_{\mathrm{tube}}\) in Angstroms.
Natoms	N atoms.
Natoms_list	list of Natoms per nanotube in bundle.
Natoms_per_bundle	Alias for Natoms.
Natoms_per_tube	Alias for Natoms_list.
Natoms_per_wall	Alias for MWNT.Natoms_list
Ntubes	Number of nanotubes in bundle.
Nwalls	Number of MWNT walls.
T_list	Length of MWNT unit cell \(|\mathbf{T}|\) in Å.
atoms	Structure Atoms.
basis	NanoStructureBase basis objects.
bundle_density	Compute the nanotube bundle density.
bundle_geometry	Bundle geometry.
bundle_mass	An alias for mass.
bundle_packing	Bundle packing.
chiral_set	Set of all chiral types in MWNT.
chiral_types	List of chiral types for each MWNT wall.
crystal_cell	Structure CrystalCell.
dt	MWNT wall diameters \(d_t=\frac{|\mathbf{C}_h|}{\pi}\) in Å.
dt_list	List of MWNT SWNT wall diameters dt \(d_t=\frac{|\mathbf{C}_h|}{\pi}\) in Å.
element1	Basis element 1
element2	Basis element 2
fmtstr	Format string.
lattice	Structure Crystal3DLattice.
lattice_shift	Lattice displacement vector.
mass	Total mass of atoms.
max_wall_diameter	Maximum wall diameter.
max_walls	Maximum number of walls.
min_wall_diameter	Minimum wall diameter.
nx	Number of nanotubes along the \(x\)-axis.
ny	Number of nanotubes along the \(y\)-axis.
nz	Number of nanotube unit cells along the \(z\)-axis.
nz_list	Number of nanotube unit cells along the \(z\)-axis.
rt	MWNT wall radii \(r_t=\frac{|\mathbf{C}_h|}{2\pi}\) in Å.
rt_list	List of MWNT SWNT wall radii rt \(r_t=\frac{|\mathbf{C}_h|}{2\pi}\) in Å.
scaling_matrix	CrystalCell.scaling_matrix.
structure	An alias to self.
tube_mass	An alias for mass.
unit_cell	Structure UnitCell.
vdw_distance	Van der Waals distance.
vdw_radius	Van der Waals radius
wall_diameters	Alias for MWNTMixin.dt_list.
wall_masses	List of MWNT SWNT wall diameters dt \(d_t=\frac{|\mathbf{C}_h|}{\pi}\) in Å.
wall_radii	Alias for MWNTMixin.rt_list.
wall_spacing	Wall-to-wall spacing.
walls	List of MWNT SWNT wall structures.

Methods

clear()	Clear list of StructureMixin.atoms.
finalize()	Finalize structure data by clipping region bounds if fix_Lz is True.
generate([finalize])	Generate structure data.
generate_Ch_list([Nwalls, max_walls, ...])	Generate list of chiralities.
generate_bundle_coords()	Generate coordinates of bundle tubes.
generate_dt_mask(dt[, max_dt_diff])	Generate boolean mask array.
generate_fname([Ch_list, Nwalls, Ntubes, ...])	Generate a filename string.
generate_unit_cell()	Generate Nanotube unit cell.
get_wall(Ch)	Return the SWNT structure with chirality Ch.
init_bundle_parameters()	Initialize bundle attributes.
make_supercell(scaling_matrix[, wrap_coords])	Make supercell.
rotate(**kwargs)	Rotate crystal cell lattice, basis, and unit cell.
save([fname, outpath, structure_format, ...])	Save structure data.
todict()	Return dict of constructor parameters.
transform_lattice(scaling_matrix[, ...])	Transform structure lattice.
translate(t[, fix_anchor_points])	Translate crystal cell lattice, basis, and unit cell.
update_Ch_list([Nwalls, min_wall_diameter, ...])	Update MWNTMixin.Ch_list.
write(*args, **kwargs)	Write structure data to file.
write_data(**kwargs)	Write LAMMPS data file.
write_dump(**kwargs)	Write LAMMPS dump file.
write_pdb(**kwargs)	Write pdb file.
write_xyz(**kwargs)	Write xyz file.

Methods Summary

finalize()	Finalize structure data by clipping region bounds if fix_Lz is True.
generate_fname([Ch_list, Nwalls, Ntubes, ...])	Generate a filename string.
save([fname, outpath, structure_format, ...])	Save structure data.

Methods Documentation

finalize()

Finalize structure data by clipping region bounds if fix_Lz is True.

classmethod generate_fname(Ch_list=None, Nwalls=None, Ntubes=None, Lz=None, nx=None, ny=None, nz=None, bundle_geometry=None, bundle_packing=None, **kwargs)

Generate a filename string.

save(fname=None, outpath=None, structure_format=None, center_centroid=True, **kwargs)

Save structure data.

See save method for documentation.