Enhancing coherence in molecular spin qubits, without resorting to extreme dilution, has been achieved by the design of molecular structures with crystal field ground states possessing large tunnelling gaps . This inspires the first learning outcome: the large off-diagonal anisotropy parameters in Y1-xLnxW30 (induced by 5-fold axial symmetry) contribute to narrowing resonance peaks in electron paramagnetic resonance (EPR) spectra with increases in Ln concentration. This suggests that the spin dynamics in Y1-xLnxW30 could be dominated by fast tunnelling processes and be strongly affected by hyperfine interactions and external magnetic fields. For C5 symmetry, the crystal field Hamiltonian can be expressed in terms of the operator equivalents :