Open Computational Chemistry

Welcome

Welcome to the official API documentation for the Open Computational Chemistry project.

Note that this is the documentation for the code - not how to use the programs. If you are looking for tutorials, please visit the website:

A simple Hartree-Fock program

Here's a very brief example, indicative of the overall design of the program, implementing a very simple spin-restricted Hartree-Fock program.

#include <occ/qm/hf.h>
#include <occ/qm/scf.h>
#include <occ/io/xyz.h>
 
int main(int argc, char argv**) {
   using occ::qm::HartreeFock;
   using occ::qm::SpinorbitalKind;
   using occ::scf::SCF;
 
   // read in a molecule from a file
   auto mol = occ::io::molecule_from_xyz_file("water.xyz");
   // load the Gaussian-type basis set for the molecule
   auto bs = occ::qm::AOBasis::load(mol.atoms(), "6-31G");
 
   // Initialize a Hartree-Fock object for restricted spinorbitals
   // with this basis set
   HartreeFock<SpinorbitalKind::Restricted> hf(bs);
 
   // Initialize an SCF object to evaluate the ground state.
   SCF<HartreeFock, SpinorbitalKind::Restricted> scf(hf);
 
   // Perform the SCF iterations and get the resulting ground state energy.
   double e = scf.compute_scf_energy();
 
   return 0;
}