Electronic and optical properties of $$\hbox {Nb}_{2}\hbox {O}_{5}$$ polymorphs: a first-principles study applying quasi-particle theory

Table 1 Calculated low-frequency ($\varepsilon _{\omega = 0}$) dielectric tensors for the B, R, P, and T polymorphs of $\hbox {Nb}_2\hbox {O}_5$

B		$\left( \begin{array}{ccc} 41.46 & 0 & -14.28 \\ 0 & 25.89 & 0 \\ -14.28 & 0 & 20.26 \end{array}\right)$
P		$\left( \begin{array}{ccc} 52.53 & 0 & 0 \\ 0 & 52.53 & 0 \\ 0 & 0 & 43.81 \end{array}\right)$
R		$\left( \begin{array}{ccc} 26.25 & 0 & 4.16 \\ 0 & 27.71 & 0 \\ 4.16 & 0 & 12.17 \end{array}\right)$
T		$\left( \begin{array}{ccc} 59.13 & 1.75 & 0 \\ 1.75 & 106.88 & 0 \\ 0 & 0 & 7.10 \end{array}\right)$

B		\(\left( \begin{array}{ccc} 41.46 & 0 & -14.28 \\ 0 & 25.89 & 0 \\ -14.28 & 0 & 20.26 \end{array}\right)\)
P		\(\left( \begin{array}{ccc} 52.53 & 0 & 0 \\ 0 & 52.53 & 0 \\ 0 & 0 & 43.81 \end{array}\right)\)
R		\(\left( \begin{array}{ccc} 26.25 & 0 & 4.16 \\ 0 & 27.71 & 0 \\ 4.16 & 0 & 12.17 \end{array}\right)\)
T		\(\left( \begin{array}{ccc} 59.13 & 1.75 & 0 \\ 1.75 & 106.88 & 0 \\ 0 & 0 & 7.10 \end{array}\right)\)