In contrast, there are three interactions specific to the low-spin d 7 species 3 and 4 that most strongly differentiate their electronic structures from 1 and 2. The first factor is coordination geometry around the Co centers. In 3 and 4, each Co mononuclear fragment has an approximately trigonal bipyramidal geometry, with axial terminal hydride and N ligands and with P, Si, and bridging hydride in the equatorial plane. In this geometry, the Co 3d orbitals transform as a1' (3𝑑 𝑧 2 ), e' (3𝑑 𝑥 2 -𝑦 2 , 3𝑑 𝑥𝑦 ), and e'' (3𝑑 𝑥𝑧 , 3𝑑 𝑦𝑧 ), with a1' significantly destabilized due to direct overlap with the axial ligands. In the dinuclear complex, the neighboring Co distorts the final geometry towards a pseudo-octahedral structure, resulting in energetic convergence of the 3𝑑 𝑥𝑦 , 3𝑑 𝑥𝑧 , and 3𝑑 𝑦𝑧 orbital energies (t2g symmetry) and destabilization of 3𝑑 𝑥 2 -𝑦 2 towards the 3𝑑 𝑧 2 level (eg symmetry). This final Oh symmetry allows for overlap of the Co 3𝑑 𝑥 2 -𝑦 2 orbitals, which are oriented along the Co-Co axis. Calculations show the formation of a multicentered bonding MO containing both direct Co-Co σ-interaction and overlap mediated by the bridging silane ligands, which stabilizes the Co 3𝑑 𝑥 2 -𝑦 2 based MO ~1.2 eV lower in energy than the average Co 3d t2g (Figure ). In 3 (and 4), this MO is composed of 29.0% (18.8%) Co 3d, 14.3% (15.5 %) Co 4p, and 16.6 % (18.7 %) Si 3p character (Table ). A corresponding vacant MO is observed featuring Co-Co σ*-antibonding character. Co-Co Mayer bond orders of 0.31 (3) and 0.28 (4) are consistent with a moderate direct Co-Co interaction and are higher than in 1 and 2 (values of 0.12 and 0.14, respectively). Lastly, strong σ overlap between Co 3𝑑 𝑧 2 and the terminal H 1s is observed, resulting from the short Co-H bond distance of about 1.48 Å. The Co-H σ-bond results in an occupied Co 3𝑑 𝑧 2 -H 1s based MO 1.0 eV lower in energy than the Co-Co σ-bonding MO, and a vacant σ*-antibonding MO 1.3 eV higher than the Co-Co antibonding MO (Figure ). These MOs also contain notable N 2p character, from overlap with the tBuPNNP ligand. The most significant is the direct Co-Co and multicentered σ-bonding MO described above (Figures ). The high Co 4p character (14.3% in 3, 15.5% in 4) in this donor MO leads to the intense feature at ~7703.0 eV (Table ). At lower energy, intense transitions result from the donor Co 3𝑑 𝑧 2 -H 1s σ-bonding MO at ~7699.9 eV. The high-energy emission feature at ~7705.6 eV is due to transitions from occupied Co 3d t2g levels. The Co K-edge XAS and Kβ v2c XES probe Co-Co and Co-H interactions from both the bonding and antibonding MO perspectives, and taken together, provide evidence of a moderate direct Co-Co σ-bond in 3 and 4.