Computer‐generated formulas for some three‐center molecular integrals over Slater‐type orbitals

Exact computer‐generated formulas can be produced for each term of an infinite series that gives the value of three‐center Coulomb integrals over Slater‐type orbitals of the s‐type with equal screening constants. As a specific example, the Coulomb energy of an equilateral triangular arrangement of all 1s orbitals is calculated using seven terms of an infinite expansion to obtain an answer comparable to earlier work in elliptic coordinates. Generalization to all three‐center cases of this implementation of the Löwdin α‐function method is straightforward.