It seems to me that Hamiltonians which are written in reciprocal space and not in real space, might become of interest especially wrt. 3d-magnetic materials. See for example the paper of the Motome group on 3D-hedgehog lattices: https://arxiv.org/abs/1908.05044
It might be worth considering whether such a feature could be provided in Spirit.
One would need to check where and how to calculate the necessary Fourier transforms to go from real to reciprocal space and back. One option would be to just calculate once the real space parameters from the reciprocal ones. For the gradient this might be best, for the energy this might be unnecessary, but I'm not sure yet.
It seems to me that Hamiltonians which are written in reciprocal space and not in real space, might become of interest especially wrt. 3d-magnetic materials. See for example the paper of the Motome group on 3D-hedgehog lattices: https://arxiv.org/abs/1908.05044 It might be worth considering whether such a feature could be provided in Spirit. One would need to check where and how to calculate the necessary Fourier transforms to go from real to reciprocal space and back. One option would be to just calculate once the real space parameters from the reciprocal ones. For the gradient this might be best, for the energy this might be unnecessary, but I'm not sure yet.