# Sle operators.m

Wigner D function basis set and rotation generators required by the gridfree.m context.

## Syntax

    [Lx,Ly,Lz,D,space_basis]=sle_operators(max_rank)


## Description

The function returns matrix representations of the angular momentum operators in the basis of Wigner D functions, matrix representations of Wigner D function product operators, and a descriptor of the basis itself.

## Arguments

    max_rank   - maximum L rank for Wigner D functions


## Returns

    space_basis  -   lab space basis set descriptor, in
[L M N] format, giving indices of
each Wigner function in the basis.

Lx,Ly,Lz  - representations of lab space rotation
generators in the Wigner function basis,
to be used in the building of the lab
space diffusion operator.

D         - a cell array of Wigner function product
superoperators, corresponding to multi-
plication by D[2,M,N] of the basis Wig-
ner functions, to be used in the build-
ing of the spin Hamiltonian operator.


## Examples

This function is used by gridfree.m context to generate the spatial basis. All SLE calculations and grid-free powder NMR calculations use that context.

## Notes

Automatic caching is implemented - the function would not recompute operator sets that it can find on disk.