Psi4 is a versatile, open source, quantum chemistry package. Psi4 is highly parallel, and has the most efficient implementation of density-fitting method. Psi4 has fast analytic gradients for many high level methods such as Møller-Plesset perturbation theory (MP2) as well as for most functional and dispersion corrections. For geometry optimizations an external optimizer, GeomeTRIC, 114 was used. GeomeTRIC uses a translation-rotation-internal coordinate (TRIC) system which significantly speeds up geometry optimizations. And for torsion scans, the TorsionDrive 57 program, which uses a wavefront propagation algorithm and multiple initial guesses in parallel, independent of the search direction, to avoid hysteresis in the atomic configurations involved in driving the torsion. The completed calculations can be conveniently accessed from the QCA server at any time, and from anywhere in the world.