Automated reaction path search calculations of spin-inversion mechanisms in the 6,4,2Nb + C2H4 reaction

Spin‐inversion mechanisms in O2 binding to a model heme complex revisited by density function theory calculations

“…We used the mixed‐spin (2 × 2) Hamiltonian matrix approach to optimize the spin‐inversion structures, where two potential energy surfaces with high‐spin and low‐spin multiplicities were mixed through the preassumed spin–orbit coupling parameter of 100 cm −1 . This spin–orbit coupling value was used to optimize spin‐inversion structures efficiently.…”

“…Against this background, here, we report more systematic computational results to elucidate the spin‐inversion mechanisms in O 2 binding to the model Fe(II)‐porphyrin‐imidazole complex using two different approaches. The first is the mixed‐spin Hamiltonian method, where two potential energy surfaces with different spin states are artificially coupled through spin–orbit coupling . This method enables the efficient optimization of a spin‐inversion structure of the two different potential energy surfaces as a transition state on the mixed‐spin potential energy surface.…”

Reduced-Dimensionality Quantum Dynamics Study of the 3Fe(CO)4 + H2 → 1FeH2(CO)4 Spin-inversion Reaction

“…The spin-coupled Hamiltonian approach [14][15][16][17] has been used to find the spin-inversion transition state structure, with the pre-assumed coupling parameter set to 100 cm −1 . Figure 1 shows the optimized spin-inversion structure and the potential energy profiles of the spin-mixed, triplet, and singlet states along the IRC.…”

“…We have recently developed a practical computational approach for studying spin-inversion reaction mechanisms [14][15][16][17], where the lowest-lying eigenstate of the spin-coupled Hamiltonian matrix [18] is used in the identification of reaction pathways involving spin-inversion points. In this method, two potential energy surfaces with different spin states are coupled through a pre-assumed spin-orbit coupling parameter.…”

“…In this work, we discuss the importance of multidimensional nuclear quantum effects in the 3 Fe(CO) 4 + H 2 → 1 FeH 2 (CO) 4 spin-inversion reaction by applying transition state wave packet calculations [29,30] combined with the above-mentioned spin-coupled Hamiltonian approach [14][15][16][17]. We here develop the reduced-dimensionality potential energy surfaces as a function of three nuclear degrees-of-freedom and then calculate the cumulative reaction probability, which is the most important physical quantity for calculating thermal rate constants [29,30].…”