Table 3.

Values of the $\overrightarrow{k}\cdot \overrightarrow{p}$ parameters obtained fitting the DFT dispersion relations.

$\overrightarrow{\mathit{k}}\cdot \overrightarrow{\mathit{p}}$ parameter	value fitted from DFT
ε 1	−2.7173 · 10−4 eV
γ	2.9360 · 10−1 eV · nm
ε 3′	1.7506 · 10−1 eV
V 6	4.6869 · 10−1 eV
c 3	3.5993 · 10−3 eV · nm2
c 4	7.2639 · 10−1 eV · nm
c 5	5.5394 · 10−2 eV · nm2
c 6	−8.3891 · 10−2 eV · nm2
c 7	−1.3307 · 10−1 eV · nm2
d 1	−3.8364 · 10−2 eV
d 2	4.6786 · 10−2 eV
f 1	−5.5095 · 10−2 eV
f 2	1.1570 · 10−1 eV
f 3	2.4084 · 10−1 eV

A $\overrightarrow{k}\cdot \overrightarrow{p}$ description with 4 bands near $\overrightarrow{K}$ and 6 bands near $\overrightarrow{\mathrm{\Gamma }}$ is considered.