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arXiv · 1405.5642

DMRG-SCF study of the singlet, triplet, and quintet states of oxo-Mn(Salen)

Sebastian Wouters·Thomas Bogaerts·Pascal Van Der Voort·Veronique Van Speybroeck·Dimitri Van Neck
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Abstract

We use CheMPS2, our free open-source spin-adapted implementation of the density matrix renormalization group (DMRG) [Wouters et al., Comput. Phys. Commun. 185, 1501 (2014)], to study the lowest singlet, triplet, and quintet states of the oxo-Mn(Salen) complex. We describe how an initial approximate DMRG calculation in a large active space around the Fermi level can be used to obtain a good set of starting orbitals for subsequent complete-active-space or DMRG self-consistent field (CASSCF or DMRG-SCF) calculations. This procedure mitigates the need for a localization procedure, followed by a manual selection of the active space. Per multiplicity, the same active space of 28 electrons in 22 orbitals (28e, 22o) is obtained with the 6-31G*, cc-pVDZ, and ANO-RCC-VDZP basis sets (the latter with DKH2 scalar relativistic corrections). Our calculations provide new insight into the electronic structure of the quintet.

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Sebastian Wouters, Thomas Bogaerts, Pascal Van Der Voort, Veronique Van Speybroeck, Dimitri Van Neck. 2014-06-18. DMRG-SCF study of the singlet, triplet, and quintet states of oxo-Mn(Salen). https://doi.org/10.1063/1.4885815

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