Pancake bonding has almost exclusively been discussed in terms of dimers of π-delocalized systems, such as tetracyanoquinodimethane or phenalenyls. In the solid state the structural diversity is richer and pancake bonded systems can be structurally characterized as either: (i) dimers in which the radicals exhibit slight distortions from planarity or (ii) equidistant face-to-face stacking of planar radicals, i.e., similar to the case we predict in K3C6O6. However, equidistant stacking is rare and such examples are in general composed of neutral radicals (or diradicals, e.g., in compounds containing CN2E2 [E=S, Se] groups) 70 that are semiconducting. Aside from the rhodizonate-based materials already mentioned (which are distorted and dimeric), the closest experimentally known analog to our predicted P6/mmm phase of K3C6O6 is probably potassium tetracyanoquinodimethane (K + TCNQ •-). The radicals in K + TCNQ •-are equidistantly stacked above 396 K, but undergo a Peierls distortion (dimerization) below this temperature. Salts of TCNQ are important historically, as they helped trigger a substantial interest in organic conduction in the 1970s and onwards. Several different TCNQ-based salts share a common electronic feature with K3C6O6: all have one quarter populated frontier bands. For TCNQ salts, such band occupation allows for conductivities of up to 1•10 -2 S cm -1 at high temperature. However, most related TCNQ-based materials that feature dimeric structures are semiconducting. For comparison, known semiconducting rhodizonate-based MOFs, such as FeC6O6, have conductivities in the mS range or below near ambient conditions. In contrast, both K3C6O6 and the P1 phase of K3.5C6O6 are predicted to be distinctly metallic regardless of if they stack equidistantly or not. Owing to this robustness of metallicity, which is ensured by favorable frontier orbital topology (Figures ), we suggest that rhodizonates with a charge near -3 can be considered design templates for one-dimensional conductors. One reason behind this suggestion is the unusually large number of electrons at the Fermi level, N, in K3C6O6: it is approximately 0.19 -0.27 states/eV/atom, depending on the level of theory (Figure ). Such high values are to the best of our knowledge unprecedented for a molecular conductor. For comparison, elemental Cu has 0.29 states/eV/atom at the Fermi Level. Meanwhile superconductors like MgB2 75 and SH3 show corresponding values of 0.24 and 0.13 states/eV/atoms, respectively, the latter requiring a pressure of around 200 GPa. Our prediction for the Fermi level DOS is sensitive to levels of theory (Figure ). However, regardless of the exact value of the Fermi level DOS, the distance between stacked anions offers a means for rationally controlling electrical conductivity. If the stacking distance is increased, the dispersion of the frontier π-bands decreases. Because the Van Hove singularities lie just below the Fermi level (Figure ), a lower dispersion will increase N. Raising the temperature induces lattice expansion, which is why we expect K3C6O6 to exhibit the rare phenomenon of a negative temperature coefficient of resistivity. In other words, at higher temperatures K3C6O6 should mascarade as a semi-conductor. Besides physical manipulation, such as raising temperatures or subjecting the material to strain or pressure, electrical conductivity might through the same argument be modulated by replacing counter cations. For example, by substituting K + for larger ions such as Rb + or Cs + higher values of N are expected. We aim to explore this hypothesis in forthcoming work.