We show that [Er-Ce-Er] molecular trinuclear coordination compound is a promising platform to implement the three-qubit quantum error correction code protecting against pure dephasing, the most important error in magnetic...

A HYSCORE investigation of the heme center in the cytochrome b559 is presented. To assign the observed signals to specific nuclei, bis-imidazol coordinated heme compounds that model the iron environment in cytochrome b559 are also studied. In the model compounds selective isotopic substitution of nitrogen atoms has been performed. The HYSCORE spectra allow us to obtain the hyperfine and quadrupolar coupling tensors of heme and imidazol bonding nitrogen atoms. The results can be interpreted in terms of the structure and the electronic distribution of the active center. The hyperfine tensors indicate that the unpaired electron is confined in a nonbonding iron orbital with a negligible nitrogen p orbital contribution. Quadrupolar coupling tensors suggest that the orientation of the semioccupied orbital is driven by the orientation of the two parallel imidazol rings of the axial histidine side chains. The results are discussed in terms of the structure-function relationship of cytochromes.