1. Choose a basis set of functions $$f_i$$ consisting of the valence atomic orbitals on each atom in the system, or some chosen subset of these orbitals.
2. With the help of the appropriate character table, determine which irreducible representations are spanned by the basis set using Equation (15.20) to determine the number of times $$a_k$$ that the $$k^{th}$$ irreducible representation appears in the representation. $a_k = \dfrac{1}{h}\sum_C n_C \chi(g) \chi_k(g) \label{22.1}$
3. Construct the SALCs $$\phi_i$$ that transform as each irreducible representation using Equation 16.1 $\phi_i = \sum_g \chi_k(g) g f_i \label{22.2}$