skip to main content

DOE PAGESDOE PAGES

Title: Molecular and electronic structures of M 2O 7 (M = Mn, Tc, Re)

The molecular and electronic structures for the Group 7b heptoxides were investigated by computational methods as both isolated molecules and in the solid-state. The metal-oxygen-metal bending angle of the single molecule increased with increasing atomic number, with Re 2O 7 preferring a linear structure. Natural bond orbital and localized orbital bonding analyses indicate that there is a three-center covalent bond between the metal atoms and the bridging oxygen, and the increasing ionic character of the bonds favors larger bond angles. The calculations accurately reproduce the experimental crystal structures within a few percent. Analysis of the band structures and density of states shows similar bonding for all of the solid-state heptoxides, including the presence of the three-center covalent bond. DFT+U simulations show that PBE-D3 underpredicts the band gap by ~0.2 eV due to an under-correlation of the metal d conducting states. As a result, homologue and compression studies show that Re 2O 7 adopts a polymeric structure because the Re-oxide tetrahedra are easily distorted by packing stresses to form additional three-center covalent bonds.
Authors:
ORCiD logo [1] ;  [1] ; ORCiD logo [1] ;  [1] ;  [2] ;  [1] ; ORCiD logo [1]
  1. Univ. of Nevada, Las Vegas, NV (United States)
  2. Univ. of Nevada, Las Vegas, NV (United States); Argonne National Lab. (ANL), Lemont, IL (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357; NA0003180
Type:
Accepted Manuscript
Journal Name:
Inorganic Chemistry
Additional Journal Information:
Journal Volume: 56; Journal Issue: 5; Journal ID: ISSN 0020-1669
Publisher:
American Chemical Society (ACS)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States); Univ. of California, Berkeley, CA (United States). Nuclear Science and Security Consortium
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA); USDOE Office of Nuclear Energy (NE)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1372697
Alternate Identifier(s):
OSTI ID: 1405178