The 10 independent components of the Ricci tensor are encoded into 4 real scalars { Φ Φ 00 , Φ Φ 11 , Φ Φ 22 , Λ Λ } and 3 complex scalars { Φ Φ 10 , Φ Φ 20 , Φ Φ 21 } (with their complex conjugates),