Comprehensive picture of ${\mathbf{VO}}_{\mathbf{2}}$ from band theory

The structural, electronic, and magnetic features of the metal-insulator transition from the tetragonal rutile ($R$) to the monoclinic ($M1$) phase of ${\mathrm{VO}}_2$ are well reproduced by band theory using the modified Becke-Johnson exchange potential. Based on this description, we identify a tendency for monoclinic charge ordering in the $R$ phase due to electronic correlations as the origin of the phase transition. Whereas, the structural changes are crucial for the gap opening in the $M1$ phase, spin degeneracy in both phases is stabilized by correlation-induced delocalization of the $\mathrm{V}3d$ electrons.

Figure 1

Atomic positions in the V-O plane in the (a) $R$ and (b) $M1$ phases. V and O atoms are indicated by large and small spheres, respectively.

Figure 2

DOS of the (a), (c), and (e) $R$ and (b), (d), and (f) $M1$ phases of ${\mathrm{VO}}_2$ obtained by (a) and (b) LDA, (c) and (d) GGA, and (e) and (f) mBJLDA calculations. The total DOS is indicated by thick solid lines, whereas, thin solid and dashed lines represent the partial $\mathrm{V}3d$ and $\mathrm{O}2p$ DOS.

Figure 3

Electronic band structures of the (a), (c), and (e) $R$ and (b), (d), and (f) $M1$ phases of ${\mathrm{VO}}_2$ obtained by (a) and (b) LDA, (c) and (d) GGA, and (e) and (f) mBJLDA calculations.

Figure 4

$\mathrm{V}3d$ charge density distributions in the V-O plane obtained for the $R$ phase by (a) LDA and (b) mBJLDA calculations.