This is a C version of the SCF code found in Appendix B of Modern Quantum Chemistry, An Introduction to Electronic Structure Theory by A. Szabo and N. Ostlund. I have included a built executable "scf_basic_version_1_0" and an output file called "out" which lists the results. Run the command "make" to build this. Note that this software is not designed to be either efficient in terms of performance or in terms of coding. It is designed as a bit of fun to convert the original Fortran IV code into something a bit more modern - C and also to demonstrate the key principles of the SCF routine when calculating the HeH+ molecule. Limited to STO-nG (n=1, 2 or 3) series basis set and 2 atoms only.