Hartree-Fock code for total energy calculations within Pople's STO-3G basis set.

Other STO-kG basis sets can be easily added. The general implementation follows reference [1].
One- and two-electron integrals were originally implemented using analytical results as explained in Reference [2] (very slow). Overlap and multiplole integrals are now implemented using the Obara-Saika scheme as presented in Regerence [3].

First iteration of the program. Restructed Hartree-Fock (RHF) calculations only. Extremely slow.

Second iteration of the program. RHF and Unrestricted Hartree-Fock (UHF). Much faster, but only because of compiler optimization.

Total energy derivatives with respect to nuclear coordinates are computed using finite differences (very unefficient). Born-Oppenheimer molecular dynamics (BOMD) is not working.

• BOMD is broken.

• Reduce libraries requirements.
• Faster implementation of one- and two-electron integrals.
• Analytical derivatives.
• Fix BOMD.
• Visualization of molecular orbitals.

[1] A. Szabo and N. S. Ostlund, Modern Quantum Chemistry: Introduction to Advanced Electronic Structure Theory, Dover Publications (1996).

[2] D. Cook, Handbook of Computational Chemistry, Oxford University Press (1998).

[3] T. Helgaker, P. Jørgensen and J. Olsen, Molecular Electronic-Structure Theory, Wiley (2000).*