- #1
Armani
- 8
- 0
Hello,
I have to calculate the cut-off energy of Beryllium that have hcp structure with the paramters: a=2.29Å and c=3.58Å.
WHAT I HAVE DONE SO FAR:
Using plane (100) or (010)
Since the formula is: $$E=\frac{1}{2} \times G^2$$
$$G=\frac{2 \Pi}{2d} $$
$$\frac{1}{d^2} = \frac{4}{3} \times \frac{h^2+h \times k+k^2}{a^2}+\frac{l^2}{c^2}$$ ---> $$d=1.98 \times 10^{-10}$$
So
$$G= 3.168208497 \times 10^{10}$$
and finally
$$E=5.018772540 \times 10^{20}$$
BUT the SOLUTION says that E=5.22 meV. Can someone correct my calculation?
I have to calculate the cut-off energy of Beryllium that have hcp structure with the paramters: a=2.29Å and c=3.58Å.
WHAT I HAVE DONE SO FAR:
Using plane (100) or (010)
Since the formula is: $$E=\frac{1}{2} \times G^2$$
$$G=\frac{2 \Pi}{2d} $$
$$\frac{1}{d^2} = \frac{4}{3} \times \frac{h^2+h \times k+k^2}{a^2}+\frac{l^2}{c^2}$$ ---> $$d=1.98 \times 10^{-10}$$
So
$$G= 3.168208497 \times 10^{10}$$
and finally
$$E=5.018772540 \times 10^{20}$$
BUT the SOLUTION says that E=5.22 meV. Can someone correct my calculation?