As indicated in the top right corner of Figure , the QM calculations required by JOYCE3.0 pa- [3,3,3] propellane,, II:poly(2,7-pyrenylene), III: n-tetradecane, IV: ethylene terephtalate, V: rPSB11, VI: [Ni(salpn)] complex, VII: dithiophene, see Figure ) are classified according to either their chemical class or the stiffness of their structure. a) level of theory (method/basis set) at which Hessian matrices and relaxed torsional energy scan were computed; b) Polycyclic Aromatic Hydrocarbon; c) Hessian matrix and torsional scans were computed for the ground and the first excited state.