- #1
Petar Mali
- 290
- 0
[tex]S=
\begin{bmatrix} a & 0 & 0 \\ 0 & a & 0 \\ 0 & 0 & a \end{bmatrix}
[/tex]
for simple cubic
[tex]I=
\begin{bmatrix} -\frac{a}{2} & \frac{a}{2} & \frac{a}{2} \\ \frac{a}{2} & -\frac{a}{2} & \frac{a}{2} \\ \frac{a}{2} & \frac{a}{2} & -\frac{a}{2} \end{bmatrix}
[/tex]
for volume centered cubic
[tex]F=
\begin{bmatrix} 0 & \frac{a}{2} & \frac{a}{2} \\ \frac{a}{2} & 0 & \frac{a}{2} \\ \frac{a}{2} & \frac{a}{2} & 0 \end{bmatrix}
[/tex]
for face centered cubic
I don't see any logic for this matrices? How can I get this? I can axcept that simple is P because minimum distance between neighbors is [tex]a[/tex]. But But what with the other two matrices?
\begin{bmatrix} a & 0 & 0 \\ 0 & a & 0 \\ 0 & 0 & a \end{bmatrix}
[/tex]
for simple cubic
[tex]I=
\begin{bmatrix} -\frac{a}{2} & \frac{a}{2} & \frac{a}{2} \\ \frac{a}{2} & -\frac{a}{2} & \frac{a}{2} \\ \frac{a}{2} & \frac{a}{2} & -\frac{a}{2} \end{bmatrix}
[/tex]
for volume centered cubic
[tex]F=
\begin{bmatrix} 0 & \frac{a}{2} & \frac{a}{2} \\ \frac{a}{2} & 0 & \frac{a}{2} \\ \frac{a}{2} & \frac{a}{2} & 0 \end{bmatrix}
[/tex]
for face centered cubic
I don't see any logic for this matrices? How can I get this? I can axcept that simple is P because minimum distance between neighbors is [tex]a[/tex]. But But what with the other two matrices?