Get volume from box#

Computing periodic cell volume directly from 3x3 box matrices.

The function molsysmt.pbc.get_volume_from_box() computes the scalar volume of a periodic boundary condition unit cell from its \(3\times 3\) box matrix (via the scalar triple product \(\mathbf{a} \cdot (\mathbf{b} \times \mathbf{c})\)).

Added in version 1.0.0.

API documentation

Follow this link for a detailed description of the input arguments, raised errors, and returned objects of this function: molsysmt.pbc.get_volume_from_box().

Basic usage#

Let’s compute the volume of cubic and truncated octahedral periodic boxes:

import molsysmt as msm
import pyunitwizard as puw

box_cub = msm.pbc.get_box_with_shape(shape='cubic', length='3.0 nm')
vol_cub = msm.pbc.get_volume_from_box(box_cub)
print('Cubic box volume (nm^3):', vol_cub)

Cubic box volume (nm^3): [27.0] nanometer ** 3

Computing volumes for non-orthogonal boxes#

The volume calculation accounts for skew angles in non-orthogonal cells:

box_oct = msm.pbc.get_box_with_shape(shape='truncated octahedral', length='3.0 nm')
vol_oct = msm.pbc.get_volume_from_box(box_oct)
print('Truncated octahedral volume (nm^3):', vol_oct)

Truncated octahedral volume (nm^3): [20.78460969082653] nanometer ** 3