# sknano.structures.compute_T¶

sknano.structures.compute_T(*Ch, *, bond=None, length=True, **kwargs)[source][source]

Compute length of nanotube unit cell $$|\mathbf{T}|$$ in Å.

$|\mathbf{T}| = \frac{\sqrt{3} |\mathbf{C}_{h}|}{d_{R}} = \frac{\sqrt{3}a\sqrt{n^2 + m^2 + nm}}{d_{R}} = \frac{3a_{\mathrm{CC}}\sqrt{n^2 + m^2 + nm}}{d_{R}}$
Parameters: *Ch : {tuple or ints} 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 length : bool, optional Compute the magnitude (i.e., length) of the translation vector. float or 2-tuple of ints If length is True, then return the length of unit cell in Å. If length is False, return the componets of the translation vector as a 2-tuple of ints ($$t_1$$, $$t_2$$).