SALC Ammonia – Molecular Orbitals

Specific combinations of atomic orbitals are use to build molecular orbitals.

As seen here the p_z orbital, like the 1s and 2s orbitals, has A₁ symetry; they are totally symmetric to the operations of the C_3v point group.

The p_x and p_y are affected by the C_3v point group operations by equal amounts and hence are degenerate. These atomic orbitals have e symmetry as defined by the character table.

Hence a combination of the appropriate atomic orbital on Nitrogen with the appropriate Symmetry Adapted Linear Combination (SALC) of hydrogen 1s orbitals generates the molecular orbitals shown above.
SALC – Ammonia Atomic Orbitals

Orbital-orbital overlap and SALC Homepage