# 3.5.5. horton.grid.molgrid – Molecular integration grids¶

class horton.grid.molgrid.BeckeMolGrid(*args, **kwargs)

Arguments:

centers
An array (N, 3) with centers for the atom-centered grids.
numbers
An array (N,) with atomic numbers.

Optional arguments:

pseudo_numbers
An array (N,) with effective core charges. When not given, this defaults to numbers.
agspec
A specifications of the atomic grid. This can either be an instance of the AtomicGridSpec object, or the first argument of its constructor.
k
The order of the switching function in Becke’s weighting scheme.
random_rotate
Flag to control random rotation of spherical grids.
mode

Select one of the following options regarding atomic subgrids:

• 'discard' (the default) means that all information about subgrids gets discarded.
• 'keep' means that a list of subgrids is kept, including the integration weights of the local grids.
• 'only' means that only the subgrids are constructed and that the computation of the molecular integration weights (based on the Becke partitioning) is skipped.
eval_decomposition(*args, **kwargs)

Evaluate a spherical decomposition

Arguments:

cubic_splines
A list cubic splines, where each item is a radial function that is associated with a corresponding real spherical harmonic.
center
The center of the spherically symmetric function
output
The output array

Optional arguments:

cell
A unit cell when periodic boundary conditions are used.
eval_spline(*args, **kwargs)

Evaluate a spherically symmetric function

Arguments:

cubic_spline
A cubic spline with the radial dependence
center
The center of the spherically symmetric function
output
The output array

Optional arguments:

cell
A unit cell when periodic boundary conditions are used.
classmethod from_hdf5(grp)
integrate(*args, **kwargs)

Integrate the product of all arguments

Arguments:

data1, data2, ...
All arguments must be arrays with the same size as the number of grid points. The arrays contain the functions, evaluated at the grid points, that must be multiplied and integrated.

Optional arguments:

center=None
When given, multipole moments are computed with respect to this center instead of a plain integral.
lmax=0
The maximum angular momentum to consider when computing multipole moments
mtype=1
The type of multipole moments: 1=cartesian, 2=pure, 3=radial, 4=surface.
segments=None
This argument can be used to divide the grid in segments. When given, it must be an array with the number of grid points in each consecutive segment. The integration is then carried out over each segment separately and an array of results is returned. The sum over all elements gives back the total integral.
to_hdf5(grp)
zeros()
agspec

The specifications of the atomic grids.

becke_weights

The becke weights of the grid points

centers

The positions of the nuclei

k

The order of the Becke switching function.

mode

The MO of this molecular grid

numbers

The element numbers

points

The grid points.

pseudo_numbers

The effective core charges

random_rotate

The random rotation flag.

shape

The shape of the grid.

size

The size of the grid.

subgrids

A list of grid objects used to construct this grid.

weights

The grid weights.