The remaining two identified ground states, a P6/mmm phase of K3C6O6 (Figure ) and a P1 phase of K3.5C6O6 (Figure ), are both predicted to be metallic and feature perfectly planar rhodizonates that are stacked without any cations in-between them. The P6/mmm phase of K3C6O6 is the focus of the remainder of this work and we will return to discuss its close structural relationship to the P1 phase of K3.5C6O6.