Relativistic Quantum Calculations to Understand the Contribution of f-Orbitals and Chemical Bonding of Actinides with Organic Ligands

• DOI: 10.48550/arxiv.2108.06057
• Publication Date: 2021-01-01
• Authors: Srimanta Pakhira; Andy D. Zapata–Es...; Joaquín Barroso‐F...; Gustavo A. Aucar; José L. Mendoza-C...
• Keywords: Relativistic quantum chemistry; Isostructural

The nuclear waste problem is one of the main interests rare earth and actinide elements chemistry. Studies Actinide-containing compounds are at frontier applications current theoretical methods due to need consider relativistic effects approximations Dirac equation in them. Here, we employ four-component quantum calculations scalar understand contribution f-type atomic orbitals chemical bonding actinides (Ac) organic ligands. We studied structure an isostructural family made Plutonium (Pu), Americium (Am), Californium (Cf), Berkelium (Bk) atoms with redox-active model ligand; DOPO (2,4,6,8-tetra-tert-butyl-1-oxo-1H-phenoxazin-9-olate). Crystallographic structures were available validate our for all mentioned except Cf. In short, state-of-the-art performed different levels theory investigate electron correlations on geometrical energies $Ac$-DOPO$_3$ complexes ($Ac$=Pu, Am, Cf, Bk) : 1) zeroth order regular approximation (ZORA) within hybrid density functional (DFT) 2) Dirac-Hartree-Fock (4c-DHF) L\'evy-Leblond (LL) Hamiltonians. show that DFT-ZORA could be used as efficient first approximate geometry electronic properties which difficult synthesize or characterize; but knowing higher theory, like 4c-DHF, gives closer results experiments than DFT-ZORA. also spin-free geometric parameters compounds.