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With oxide charge $-2$ and four thiocyanates each $-1$, $x-2-4=-2$ gives V(IV), $d^1$. Counting the terminal oxo as $X_2$ and each thiocyanate as X givesThe expected structure is square-pyramidal molecular geometry, with the short V=O unit at the apex and the four thiocyanate donors in the basal plane. The remaining d electron can occupy an approximately basal $d_{xy}$ orbital that avoids the strongest donor directions and the oxo pi-antibonding orbitals. This is a high-oxidation-state oxovanadium complex; reaching 18 electrons is not its governing stability criterion. The displayed $\mathrm{SCN}$ composition alone does not establish N versus S linkage, and that choice does not change this count. The stated 13-electron result consistently uses a four-electron $\mathrm{M}=\mathrm{O}$ convention; counting extra oxide pi-donor interactions as additional ligand electrons requires a different convention throughout.

Start from an octahedral molecular geometry with ligands on $\pm x,\pm y,\pm z$, with $e_g=(d_{z^2},d_{x^2-y^2})$ above $t_{2g}=(d_{xy},d_{xz},d_{yz})$. Remove the $-z$ donor while keeping the other five positions. Loss of axial repulsion lowers $d_{z^2}$ substantially; $d_{x^2-y^2}$ still points directly at four basal donors and remains highest. Loss of an axial donor also lowers the orbitals with $z$ dependence relative to $d_{xy}$. The remaining fourfold axis keeps $d_{xz}$ and $d_{yz}$ degenerate.

The usual qualitative square-pyramidal molecular geometry diagram, shown in the last panel above, is thereforeThe corresponding $C_{4v}$ labels are $b_1,a_1,b_2,e$. Energies can be re-zeroed to the new orbital barycenter after ligand removal. Symmetry fixes the degeneracy and labels, but does not universally fix the separation of $d_{z^2}$ and $d_{xy}$: a weak or distant axial donor can reverse this middle pair on approach to the square-planar limit. The displayed ordering assumes an appreciable fifth axial interaction.

Square-pyramidal molecular geometry has four basal donor positions in a square and one axial donor. Removing one axial ligand from an octahedral molecular geometry lowers orbitals with $z$ character. A common $d$-level order is $d_{x^2-y^2}>d_{z^2}>d_{xy}>d_{xz}=d_{yz}$, although the middle pair depends on axial strength and distances.