CREST revealed that another conformer C corresponds to the global minimum on the potential energy surface, hence being the main conformer in both solutions. The conformer C is significantly lower in energy compared to previously found conformers A and B (+4.45 kcal . mol -1 compared to conformer A in dichloromethane and +3.25 kcal . mol -1 compared to conformer B in chloroform). In the newly found conformer C, two guests are placed in the cavities as well, and their binding modes are the same as described above. The conformer C differs from the previously found conformers only in the mutual arrangement of one of the guests, as well as the porphyrin's Et groups. In contrast to the conformers A and B, where the carbonyl oxygens of the guests are pointed to the same direction (both to the right or to the left, correspondingly, see Figure ), in the conformer C, one carbonyl oxygen is pointed to the right, whilst another to the left. The orientation of porphyrin's Et groups also changed compared to the crystal structure (vide infra). This explains why the calculated and measured NMR spectra are in agreement, but the ECD spectra are not. NMR is sensitive to the environment, hence allowing determination of neighboring atoms and their mutual position, at short ranges. In contrast, ECD is sensitive to the stereochemistry and position/geometry of chromophores, hence allowing determination of chirality of the whole complex (i.e., at larger scale). Thus, NMR (TOCSY, HSQC, HMBC, and ROESY spectra) showed how (R)-CSA is situated in the supramolecule and with which atoms the analyte is bonded, while ECD revealed how the host and two guest molecules are orientated relative to each other. The ECD spectra simulated for the newly found conformer C agree well with the experimental data in both solvents (Figures and). Nonetheless, some discrepancies are observed in the ECD intensities; however, it is known that the intensities are predicted poorer than the absorption energies by calculations. Figure . ECD spectrum of porphyrin/(R)-CSA complex of the conformer C in dichloromethane.