A density matrix renormalization group investigation on the electronic states of MnGen−/0/+ (n = 1–3) clusters

Abstract

AbstractMnGen−/0/+ (n = 1–3) clusters have complicated geometric and electronic structures. In this work, we explored the isomers and electronic states of MnGen−/0/+ (n = 1–3) clusters by using density functional theory, CASPT2, and DMRG‐CASPT2 methods. The DMRG‐CASPT2 method with active spaces up to 23 orbitals could provide accurate relative energies of the low‐lying states. The results showed that the electronic states of MnGen−/0/+ (n = 1–3) have strong multireference wave functions. The hybrid PBE0 functional was sufficient to calculate the relative energies of the electronic states of manganese‐doped germanium clusters. The leading configurations, bond distances, bond orders, harmonic vibrational frequencies, relative energies, and electron detachment energies of the relevant electronic states of MnGen−/0/+ (n = 1–3) were reported. The computational results in this work showed that the DMRG‐CASPT2 method with large active spaces can be employed to study the structures and properties of transitional metal‐containing clusters with strong electron correlation effects.