spherical_harmonics#

cuequivariance.group_theory.descriptors.spherical_harmonics( ir_vec: Irrep, ls: list[int], layout: IrrepsLayout = (irrep, mul), ) → EquivariantPolynomial#

Polynomial descriptor for the spherical harmonics.

Subscripts: vector[],...,vector[],Yl[]

Parameters:

ir_vec (Irrep) – irrep of the input vector, for example cue.SO3(1).
ls (list of int) – list of spherical harmonic degrees, for example [0, 1, 2].
layout (IrrepsLayout, optional) – layout of the output. Defaults to cue.ir_mul.

Returns:

The descriptor.

Return type:

cue.EquivariantPolynomial

Example

>>> spherical_harmonics(cue.SO3(1), [0, 1, 2])
╭ a=1 -> B=0+1+2
│  []➜B[] ───────── num_paths=1
│  []·a[]➜B[] ───── num_paths=3
╰─ []·a[]·a[]➜B[] ─ num_paths=11