The document describes how to generate Slater-type orbitals (STOs) for the atoms carbon, nitrogen, and silicon. It provides the Slater rules for determining the effective nuclear charge (Z*) from the atomic number (Z) and screening constant (S). It then gives the STO expressions for the 2s, 2p, 3s, and 3p orbitals of each atom, using the appropriate Z* value calculated from the Slater rules.