Efficient implementation of one- and two-component analytical energy gradients in exact two-component theory.

We present an efficient algorithm for one- and two-component analytical energy gradients with respect to nuclear displacements in the exact two-component decoupling approach to the one-electron Dirac equation (X2C). Our approach is a generalization of the spin-free ansatz by Cheng and Gauss [J. Chem.

Solvatochromic shifts of Br₂ and I₂ in water cages of type 5¹², 5¹²6², 5¹²6³, and 5¹²6⁴.

Despite the relatively small size of molecular bromine and iodine, the physicochemical behavior in different solvents is not yet fully understood, in particular when excited-state properties are sought. In this work, we investigate isolated halogen molecules trapped in clathrate hydrate cages. Relativistic supermolecular calculations reveal that the environment shift to the excitation energies of the (nondegenerate) states 3Πu and 1Πu lie within a spread of 0.

An efficient implementation of two-component relativistic exact-decoupling methods for large molecules.

We present an efficient algorithm for one- and two-component relativistic exact-decoupling calculations. Spin-orbit coupling is thus taken into account for the evaluation of relativistically transformed (one-electron) Hamiltonian. As the relativistic decoupling transformation has to be evaluated with primitive functions, the construction of the relativistic one-electron Hamiltonian becomes the bottleneck of the whole calculation for large molecules.

[{Fe(CO)3}4{SnI}6I4]2-: the first bimetallic adamantane-like cluster.

Show some metal: the first bimetallic adamantane-like cluster, [{Fe(CO)(3)}(4){SnI}(6)I(4)](2-), was prepared by an ionic-liquid-based synthesis. The valence states of iron and tin were verified based on bond-length considerations, FT-IR and (119)Sn Mössbauer spectroscopy, as well as with DFT calculations.

[XIm][FeI(CO)3(SnI3)2] (XIm: EMIm, EHIm, PMIm) containing a barbell-shaped FeSn2-carbonyl complex.

By reacting Fe(CO)(5) and SnI(4) in the ionic liquids [XIm][NTf(2)] (XIm: 1-ethyl-3-methylimidazolium/EMIm, 1-ethyl-imidazolium/EHIm, 1-propyl-3-methylimidazolium/PMIm; NTf(2): bistrifluoridomethansulfonimide), the compounds [XIm][FeI(CO)(3)(SnI(3))(2)] are obtained as transparent, dark red crystals. According to single-crystal structure analysis, the title compounds crystallize monoclinically and contain the anionic carbonyl complex [FeI(CO)(3)(SnI(3))(2)](-) as well as [EMIm](+), [EHIm](+) or [PMIm](+) cations. The anionic carbonyl is composed of a Sn-Fe-Sn barbell-shaped building unit with Fe-Sn distances of 252.