def compute_bundle_density(*Ch,
r_vdw=None,
bond=None,
element1=None,
element2=None):
"""Compute nanotube bundle mass density \
:math:`\\rho_{\\mathrm{bundle}}(n, m)` in :math:`\\mathrm{g/cm^3}`.
.. math::
\\rho_{\\mathrm{bundle}}(n, m) = \\frac{8\\pi^2 m_{\\mathrm{C}}
\\sqrt{n^2 + m^2 + nm}}{9\\sqrt{3}a_{\\mathrm{CC}}^3 \\times
\\left(\\sqrt{n^2 + m^2 + nm} +
\\frac{\\pi d_{\\mathrm{vdW}}}{\\sqrt{3}a_{\\mathrm{CC}}}\\right)^2}
Parameters
----------
*Ch : {:class:`python:tuple` or :class:`python:int`\ s}
Either a 2-tuple of ints or 2 integers giving the chiral indices
of the nanotube chiral vector
:math:`\\mathbf{C}_h = n\\mathbf{a}_1 + m\\mathbf{a}_2 = (n, m)`.
r_vdw : int
van der Waals radius of nanotube atoms
bond : float, optional
Bond length.
Returns
-------
float
:math:`\\rho_{\\mathrm{bundle}}` in units of
:math:`\\mathrm{\\frac{g}{cm^3}}`
"""
n, m, _ = get_chiral_indices(*Ch)
if bond is None:
bond = aCC
if element1 is None:
element1 = 'C'
if element2 is None:
element2 = 'C'
if r_vdw is None:
r_vdw = vdw_radius_from_basis(element1, element2)
if element1 == element2:
bundle_density = 8 * np.pi ** 2 * Atom(element1).mass * \
np.sqrt(n ** 2 + m ** 2 + n * m) / \
(9 * np.sqrt(3) * bond ** 3 *
(np.sqrt(n ** 2 + m ** 2 + n * m) +
2 * np.pi * r_vdw / (np.sqrt(3) * bond)) ** 2)
else:
bundle_density = 0
# there are 1.6605e-24 grams / Da and 1e-8 cm / angstrom
bundle_density *= grams_per_Da / (1e-8)**3
return bundle_density
def compute_bundle_density(*Ch, r_vdw=None, bond=None,
element1=None, element2=None):
"""Compute nanotube bundle mass density \
:math:`\\rho_{\\mathrm{bundle}}(n, m)` in :math:`\\mathrm{g/cm^3}`.
.. math::
\\rho_{\\mathrm{bundle}}(n, m) = \\frac{8\\pi^2 m_{\\mathrm{C}}
\\sqrt{n^2 + m^2 + nm}}{9\\sqrt{3}a_{\\mathrm{CC}}^3 \\times
\\left(\\sqrt{n^2 + m^2 + nm} +
\\frac{\\pi d_{\\mathrm{vdW}}}{\\sqrt{3}a_{\\mathrm{CC}}}\\right)^2}
Parameters
----------
*Ch : {:class:`python:tuple` or :class:`python:int`\ s}
Either a 2-tuple of ints or 2 integers giving the chiral indices
of the nanotube chiral vector
:math:`\\mathbf{C}_h = n\\mathbf{a}_1 + m\\mathbf{a}_2 = (n, m)`.
r_vdw : int
van der Waals radius of nanotube atoms
bond : float, optional
Bond length.
Returns
-------
float
:math:`\\rho_{\\mathrm{bundle}}` in units of
:math:`\\mathrm{\\frac{g}{cm^3}}`
"""
n, m, _ = get_chiral_indices(*Ch)
if bond is None:
bond = aCC
if element1 is None:
element1 = 'C'
if element2 is None:
element2 = 'C'
if r_vdw is None:
r_vdw = vdw_radius_from_basis(element1, element2)
if element1 == element2:
bundle_density = 8 * np.pi ** 2 * Atom(element1).mass * \
np.sqrt(n ** 2 + m ** 2 + n * m) / \
(9 * np.sqrt(3) * bond ** 3 *
(np.sqrt(n ** 2 + m ** 2 + n * m) +
2 * np.pi * r_vdw / (np.sqrt(3) * bond)) ** 2)
else:
bundle_density = 0
# there are 1.6605e-24 grams / Da and 1e-8 cm / angstrom
bundle_density *= grams_per_Da / (1e-8) ** 3
return bundle_density
def vdw_radius(self):
"""van der Waals radius"""
if self._vdw_radius is not None:
return self._vdw_radius
else:
return vdw_radius_from_basis(self.basis[0], self.basis[1])
def vdw_radius(self):
"""van der Waals radius"""
if self._vdw_radius is not None:
return self._vdw_radius
else:
return vdw_radius_from_basis(self.basis[0], self.basis[1])