1. E. Clementi andD. Davis, J. Comp. Phys.,1, 223, 1966.
2. E. Clementi, J. Chem. Phys.,46, 3842, 1967; 3851, 1967; 4725, 1967; 4731, 1967; 4737, 1967; ibid.47, 2323, 1967; 3837, 1967; 4485, 1967.
3. E. Clementi, V. Coiro andE. Rusconi, J. Chem. Phys., Study in the Electronic Structure of Molecules. XII, Inner Shells and Aufbau Principle (to be published).
4. Somewhat parenthetically we would like to note that the ∼n 4 number (more accurately (N 2+N)/2, whereN=(n 2+n)/2 ifn is the basis set size) is most definitely only an upper limit. The larger the molecule (say 5 to 6 first row atom and up), the more the above statement is true since a large (up to 50 to 90%) number of integrals is exceedingly small (of the order of equal or less than 10−8 atomic units).
5. Appendix to IBM Technical Report: Study in the Electronic Structure of Molecules. X. Ground State Functions for adenine, cytosine, guanine and thyamine.