CHM 501

27. Find the irreducible representations for the σ bonds in NH3.

Answer

C3v point group:

C3v

E

2C3

v

a1

1

1

1

a2

1

1

–1

e

2

–1

0

       

σ bonds

3

0

1

n(a1) = [(1)(1)(3) + (2)(1)(0) + (3)(1)(1)]/6 = 1

n(a2) = [(1)(1)(3) + (2)(1)(0) + (3)(–1)(1)]/6 = 0

n(e) = [(1)(2)(3) + (2)(–1)(0) + (3)(0)(1)]/6 = 1

The σ orbitals in NH3 transform as a1 + e