Example to run mopac and get energy via C++

calc_mopac_energy.hpp

double calc_mopac_energy(OpenBabel::OBMol &mol) {

    OpenBabel::OBConversion conv;
    conv.SetInAndOutFormats("moo", "mop");
    std::remove("temp.mop");
    std::remove("temp.out");
    std::remove("temp.arc");
    std::ofstream ofs("temp.mop");
    conv.Write(&mol, &ofs);
    system("./run_mopac");
    ofs.close();


    std::ifstream ifs;

    OpenBabel::OBMol molout;
    ifs.open("temp.out");
    conv.Read(&molout, &ifs);
    ifs.close();
    
    return molout.GetEnergy();

}