To further understand the bonding situation in the cyanoketene anion and its electronic structure we turned our attention towards computational studies. While energy optimizations of the free anion on density functional theory (DFT) levels yielded a linear geometry of 2 independent of the applied functional and basis set (see the Supporting Information for details), a bent structure with a C-C-C angle of 150.9° was obtained on the coupled cluster level (CCSD(T)/ma-def2-TZVPP, Fig. ). However, a relaxed energy surface scan revealed a shallow bending potential, with less than 1 kcal/mol required for the widening of this angle from 150 to 180°. This corroborates well with the larger angle as well as the large thermal ellipsoids and disordered structures of 2 found in the solid-state structures (see above). Packing effects and weak cation-anion interactions may thus result in changes in the bending of the molecule. Such a shallow energy surface has also been reported for the structure of other cumulene-like compounds such as carbon suboxide. Analysis of the molecular orbitals (MO, Fig. ) of 2 reveals that the six π-symmetric orbitals comprise three pairs of MOs of similar energy, which are degenerate in the linear structure of 2 (angle fixed to 180°). In both cases, the two highest occupied molecular orbitals (HOMO and HOMO-1) span over the whole NCCCO linkage with nodal planes between the C2 and O atom as well as the central carbon atom (C1) and the CN moiety (see the Supporting Information for a detailed bonding analysis). The highest orbital coefficient is found at the C1 carbon atom suggesting that orbital-driven reactions should occur at this site. Calculated bond indices suggest the presence of a C-N triple bond and a ketene moiety C=C=O, whereas Intrinsic Atomic Orbital (IAO) analysis indicates a dominance of the cyanoethynolate structure 2c (Figure ), thus indicating an overall intermediate bonding situation between 2c and 2a. Natural Resonance Theory (NRT) revealed that the three resonance structures 2a (33.2%), 2c (24.0%) and 2d (40.0%) contribute most to the actual bonding situation with the cumulene structure 2d being the most dominant. Also, the negative charge of the anion is almost equally distributed over the C1 (qC = -0.57 e), the nitrogen (qN = -0.49 e) and oxygen atom (qO = -0.61 e). However, Quantum Theory of Atoms in Molecules (QTAIM) calculations showed bond ellipticities at the Bond Critical Points (BCP) close to 0 which argues against bonds with a significant double bond character within the anion. Overall, the computational studies agree well with the crystallographic and spectroscopic studies and an ambiguous bonding situation in the cyanoketene anion which can only be represented by a combination of different resonance forms.