Direct Energy, 2018a

36 2.3 Piezoelectric Devices
Hermann-
Mauguin
Notation
Schoenies
Notation
Crystal System Angles ofPrimitive
Lattice Cell
Lengths of
Primitive
Lattice
Cell
Piezoelec.,
Pockels
Electrooptic,
No
Inversion
Symmetry
1 C1 triclinic α, β, γ ≠90 ◦ a ≠ b ≠ c y y
1 S2 triclinic α, β, γ ≠90 ◦ a ≠ b ≠ c n n
2 C2 monoclinic α, γ =90 ◦ ,β ≠90 ◦ a ≠ b ≠ c y y
m C1h monoclinic α, γ =90 ◦ ,β ≠90 ◦ a ≠ b ≠ c y y
2
m
C2h monoclinic α, γ =90 ◦ ,β ≠90 ◦ a ≠ b ≠ c n n
222 D2, V orthorhombic α, β, γ =90 ◦ a ≠ b ≠ c y n
2mm C2v orthorhombic α, β, γ =90 ◦ a ≠ b ≠ c y y
2
m
2
m
2
m
D2h,Vh orthorhombic α, β, γ =90 ◦ a ≠ b ≠ c n n
4 C4 tetragonal α, β, γ =90 ◦ a = b ≠ c y y
4 S4 tetragonal α, β, γ =90 ◦ a = b ≠ c y n
4
m
C4h tetragonal α, β, γ =90 ◦ a = b ≠ c n n
422 D4 tetragonal α, β, γ =90 ◦ a = b ≠ c y n
4mm C4v tetragonal α, β, γ =90 ◦ a = b ≠ c y y
42m D2d,Vd tetragonal α, β, γ =90 ◦ a = b ≠ c y n
4
m
2
m
2
m
D4h tetragonal α, β, γ =90 ◦ a = b ≠ c n n
3 C3 trigonal α, β, γ ≠90 ◦ a = b = c y y
Pyroelectric
Table 2.2: Summary ofcrystal point groups.