Electron Structure of Molecules with Very Heavy Atoms Using Effective Core Potentials

Observation of an Intermediate to H2 Binding in a Metal–organic Framework

“…The CRENBL basis with the fit-CRENBL ECP employs a 6-311G* basis for H atoms and its size for heavy atoms lies in between LANL2DZp and SDB-cc-pVTZ 7 . Effective core potentials employed in the basis CRENBL with fit-CRENBL ECP are a refinement of the "shape consistent" effective potential procedure of Christiansen, Lee, and Pitzer 8 and have been employed in numerous molecular calculations [9][10][11][12] that have attested to their reliability when compared to all-electron computations. In terms of basis cardinality for valence shell electrons (X), the CRENBL basis is positioned in between double (X=D) and triple (X=T) zeta basis sets for heavy atoms, and for hydrogen it employs the triple zeta valence polarized basis 6-311G*.…”

“…While many classical examples involve electron-poor metal cations that interact with adsorbates largely through electrostatic interactions, unsaturated electron-rich metal centers housed within porous frameworks can often chemisorb guests amenable to redox activity or covalent bond formation. [5][6][7][8][9] Despite the promise that materials bearing such sites hold in addressing myriad challenges in gas separations and storage [10][11][12] , very few studies have directly interrogated mechanisms of chemisorption at open metal sites within porous frameworks. Here, we show that non-dissociative chemisorption of H 2 at the trigonal pyramidal Cu + sites in the metal-organic framework Cu I -MFU-4l 13 occurs via the intermediacy of a metastable physisorbed precursor species.…”

Opacity

“…Vector processing and parallel processing techniques play a vital role in rendering the algorithms that arise in relativistic electronic structure studies tractable (Wilson 1997d). Papers by Desclaux (1983a,b), Detrich and Roothaan (1981), Hay (1981), Ishikawa and Malli (1981), Ladik et al (1981), Malli (1981), Pitzer (1981), Pyper (1981), Yang (1981), and Ziegler (1981) discuss computational methods for including relativity effects.…”