SOC matrix

Dear SIESTA team,
in the previous paper https://wiki.physics.udel.edu/wiki_qttg/images/1/11/SIESTA%3Dfully_relativistic_pseudopotential_formalism_under_atomic_orbital_basis_spin_orbit_splittings_and_magnetic_anisotropies.pdf
it mentioned we can extract the SOC coupling matrix from FR-PS pseudopotential, but i’m not sure where can i find this information and how to extract it along with wavefunction for other implementation.

Is there any instruction?

Best,
Shimin
PhD student,
University of California, Santa Cruz