openfermion.utils.map_particle_hole_dm_to_one_pdm

Map the particle-hole-RDM to the 1-RDM

phdm (numpy.ndarray): The 2-particle-hole-RDM as a 4-index tensor. Indices follow the internal convention of phdm[p, q, r, s] == $a_{p}^{\dagger}a_{q}a_{r}^{\dagger}a_{s}$.
num_particles number of particles in the system.
num_basis_functions number of spin-orbitals (usually the number of qubits)

opdm (numpy.ndarray): the 1-RDM transformed from a 1-RDM.