Several algorithms can be utilized to prepare the ground state solution, |Ψ 9: ⟩, of a molecule by encoding the fermionic chemistry problem , (7) where ℎ 13 and 𝑉 13=> are the one-and two-electron integrals. We stress that our specific choices of algorithms and encoding procedures are not essential for the general case of calculating electron densities with a quantum computer. What is necessary is a) identification of a state of interest (in our case, the ground state) by some quantum algorithm or quantum simulation , and b) reconstruction of the 1-RDM through measurements of ⟨𝑎 1 5 𝑎 3 ⟩, following Eq. ( ).