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V 3$d$ charge and orbital states in V$_2$OPO$_4$ have been investigated bymeans of x-ray absorption spectroscopy (XAS). The electronic structure ofV$_2$OPO$_4$ is very unique in that the charge transfer between V$^{2+}$ andV$^{3+}$ in face sharing VO$_6$ chains provides negative thermal expansion asreported by Pachoud {\it et al.} [J. Am. Chem. Soc. {\bf 140}, 636 (2018).] Thenear edge region of O 1$s$ XAS exhibits the three features which can beassigned to transitions to O 2$p$ mixed into the unoccupied V 3$d$ $t_{2g}$ and$e_{g}$ orbitals of V$^{2+}$ and V$^{3+}$. The V 2$p$ XAS line shape can bereproduced by multiplet calculations for a mixed valence state with V$^{2+}$and V$^{3+}$. The polarization dependence of the O 1$s$ and V 2$p$ XAS spectraindicates V 3$d$ orbital order in which $xy$ and $yz$ (or $zx$) orbitals areoccupied at the V$^{3+}$ site in the face sharing chains. The occupied $xy$orbital is essential for the antiferromagnetic coupling between the V$^{2+}$and V$^{3+}$ sites along the chains while the occupied $yz$ (or $zx$) orbitalprovides the antiferromagnetic coupling between the V$^{2+}$ and V$^{3+}$ sitesbetween the chains.

V 3$d$ charge and orbital states in V$_2$OPO$_4$ probed by x-ray absorption spectroscopy