compute_tau

sknano.core.structures.compute_tau(*Ch, bond=None, **kwargs)

Compute translation component of symmetry operation \(\tau\) in Å.

\[\tau = \frac{M|\mathbf{T}|}{N}\]

Parameters:

• *Ch –

  Either a 2-tuple of ints or 2 integers giving the chiral indices of the nanotube chiral vector \(\mathbf{C}_h = n\mathbf{a}_1 + m\mathbf{a}_2 = (n, m)\).

• bond (float, optional) – Distance between nearest neighbor atoms (i.e., bond length). Must be in units of Å. Default value is the carbon-carbon bond length in graphite, approximately \(\mathrm{a}_{\mathrm{CC}} = 1.42\) Å

Returns:

Translation component of symmetry operation \(\tau\) in Å.

Return type:

float