molgrid.quadrature module

class molgrid.quadrature.Lebedev[source]

Bases: object

get(degree, coord='cartesian')[source]

Get points and weights for given degree

Parameters:

  • degree – Quadrature degree

  • coord – ‘cartesian’ (x,y,z) or ‘spherical’ (r,theta,phi)

Returns:

(points, weights)

get_degrees_list()[source]

Get list of available degrees

get_npoints_list()[source]

Get list of number of points for each degree

class molgrid.quadrature.GaussChebychev[source]

Bases: object

finite(nshells)[source]

Generate Gauss-Chebyshev quadrature on finite interval [-1, 1]

Parameters:

nshells (int) – Number of quadrature points

Returns:

  • x (ndarray) – Quadrature points in [-1, 1]

  • w (ndarray) – Quadrature weights (sum = pi/2 for second-kind Chebyshev)

semi_infinite(r_scale, nshells)[source]

Generate Gauss-Chebyshev quadrature on semi-infinite interval [0, infty)

Maps [-1, 1] to [0, infty) using: r = r_scale * (1 + x) / (1 - x)

Parameters:

  • r_scale (float) – Radial scaling factor

  • nshells (int) – Number of quadrature points

Returns:

  • r (ndarray) – Radial quadrature points in [0, infty)

  • w (ndarray) – Radial quadrature weights for int f(r) dr