bitals onto each other (for an overall contribution of 0). The total contribu-
tion to the character is 2, so that d2. The complete set of characters is
E 8 C 3 3 C 2 6 S 4 6 d
sp^3 4 1 0 0 2
This is not one of the irreducible representations ofTd, so the great orthogo-
nality theorem must be applied. Doing so shows that above is a combination
ofA 1 and T 2 , or rather,
A 1 T 2
13.11 Hybrid Orbitals 455
E 4
a
cb
d
a
cb
d
C 3 1
a
cb
d
a
bd
c
C 2 0
a
cb
d
b
d a
c
S 4 0
d
a c
b
d 2
a
cb
d
a
db
c
(e)
(c)
(b)
(a)
a
cb
d
(d)
Figure 13.26 Operation of the symmetry
classes ofTdon the sp^3 orbitals. The a,b,c, and d
labels are used only to keep track of the individ-
ual hybrid orbitals. The number of hybrid or-
bitals that do not move when a symmetry opera-
tion occurs is listed in the final column. This set
of numbers is the reducible representation of
the sp^3 orbitals. The great orthogonality theorem
is used to reduce into its irreducible represen-
tation labels.