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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Unraveling the Intermediate Species of Co 3 O 4 Hollow Spheres for CO 2 Photoreduction by In Situ X-ray Absorption Spectroscopy

Nanostructured hollow materials have emerged as a promising class of materials for energy conversion and storage. Herein, we report a Co 3 O 4 hollow sphere nanostructure that can serve as a CO 2 reduction catalyst to form CO with high selectivity upon visible-light illumination in the presence of a [Ru(bpy) 3 ] 2+ molecular photosensitizer. Using in situ X-ray absorption spectroscopy, we not only showed that the Co center in the Co 3 O 4 hollow sphere is the active site for CO 2 reduction but also identified a key intermediate species, that is, a reduced Co center, due to electron transfer from the [Ru(bpy) 3 ] 2+ photosensitizer when the system can steadily generate CO.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on LiAlH8C16(O2F9)4 by Materials Project

Li(H2O)4Al(CO)4(CF3)12 crystallizes in the tetragonal I-4 space group. The structure is zero-dimensional and consists of twenty-four fluoroform molecules, two Al(CO)4 clusters, and two Li(H2O)4 clusters. In each Al(CO)4 cluster, Al3+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Al–O bond lengths are 1.75 Å. C+2.50+ is bonded in a single-bond geometry to one O2- atom. The C–O bond length is 1.35 Å. O2- is bonded in a bent 150 degrees geometry to one Al3+ and one C+2.50+ atom. In each Li(H2O)4 cluster, Li1+ is bonded in a tetrahedral geometry to four equivalent O2- atoms. All Li–O bond lengths are 1.94 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.97 Å. O2- is bonded in a trigonal planar geometry to one Li1+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Os5(CO)19 by Materials Project

Os(CO)3(Os(CO)4)4 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two Os(CO)3 clusters and eight Os(CO)4 clusters. In each Os(CO)3 cluster, Os+1.20- is bonded in a T-shaped geometry to three C+2.32+ atoms. There is one shorter (1.89 Å) and two longer (1.94 Å) Os–C bond length. There are three inequivalent C+2.32+ sites. In the first C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. In the second C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.17 Å. In the third C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In two of the Os(CO)4 clusters, Os+1.20- is bonded in a rectangular see-saw-like geometry to four C+2.32+ atoms. There are a spread of Os–C bond distances ranging from 1.90–1.96 Å. There are four inequivalent C+2.32+ sites. In the first C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.15 Å. In the second C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. In the third C+2.32+ site, C+2.32+ is bonded in a linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In two of the Os(CO)4 clusters, Os+1.20- is bonded in a rectangular see-saw-like geometry to four C+2.32+ atoms. There are a spread of Os–C bond distances ranging from 1.91–1.97 Å. There are four inequivalent C+2.32+ sites. In the first C+2.32+ site, C+2.32+ is bonded in a linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. In the second C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.15 Å. In the third C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+2.32+ site, C+2.32+ is bonded in a linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In two of the Os(CO)4 clusters, Os+1.20- is bonded in a rectangular see-saw-like geometry to four C+2.32+ atoms. There are a spread of Os–C bond distances ranging from 1.91–1.96 Å. There are four inequivalent C+2.32+ sites. In the first C+2.32+ site, C+2.32+ is bonded in a linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. In the second C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. In the third C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In two of the Os(CO)4 clusters, Os+1.20- is bonded in a rectangular see-saw-like geometry to four C+2.32+ atoms. There are a spread of Os–C bond distances ranging from 1.91–1.96 Å. There are four inequivalent C+2.32+ sites. In the first C+2.32+ site, C+2.32+ is bonded in a linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. In the second C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. In the third C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+2.32+ site, C+2.32+ is bonded in a distorted linear geometry to one Os+1.20- and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+2.32+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Co3SnC12ClO12 by Materials Project

(Co(CO)4)3SnCl crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four tin chloride (sncl) molecules and twelve Co(CO)4 clusters. In four of the Co(CO)4 clusters, Co+1.67+ is bonded in a trigonal pyramidal geometry to four C+1.33+ atoms. There is two shorter (1.77 Å) and two longer (1.78 Å) Co–C bond length. There are four inequivalent C+1.33+ sites. In the first C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.33+ site, C+1.33+ is bonded in a distorted single-bond geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.15 Å. In the fourth C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In eight of the Co(CO)4 clusters, Co+1.67+ is bonded in a trigonal pyramidal geometry to four C+1.33+ atoms. There is two shorter (1.77 Å) and two longer (1.78 Å) Co–C bond length. There are four inequivalent C+1.33+ sites. In the first C+1.33+ site, C+1.33+ is bonded in a distorted single-bond geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.15 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Triplet‐Singlet Emission of d‐Block Metal Complexes Characterized by Spin‐Orbit Natural Transition Orbitals

Abstract Spin‐orbit natural transition orbital (SO‐NTO) methodology, recently developed in our group for complete and restricted active space (CAS/RAS) wavefunction calculations, is applied to analyze triplet‐to‐singlet emission in transition metal complexes. The lowest‐energy (longest‐wavelength) spin‐forbidden transition is studied for for [Ir(pbt)2(acac)] and [Re(CO)4(pbt)] and the complexes [W(CO)4(bpy)] and [Mo(CO)4(bpy)]. For the latter complexes, spin‐forbidden transitions from higher spin‐triplet levels are additionally analyzed. SO‐NTOs are compared with spin‐free NTOs for the transitions under consideration. The major assignment of a spin‐forbidden transition is obtained from the spin‐free NTO analysis, while the source of intensity of the electronic transition is revealed by the SO‐NTOs.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Fast Proton Transfer and Hydrogen Evolution Reactivity Mediated by [Co 13 C 2 (CO) 24 ] 4–

A common approach to speeding up proton transfer (PT) by molecular catalysts is manipulation of the secondary coordina-tion sphere with proton relays and these enhance overall reaction rates by orders of magnitude. In contrast, heterogenous electrocatalysts have band structures that promote facile PT concerted with electron transfer (ET), known as the Volmer mechanism. Here in this paper, we show that [Co 13 C 2 (CO) 24 ] 4– , containing multiple Co-Co bonds to statistically enhance observed rates of PT, promotes PT on the order of 2.3 × 10 9 M -1 s -1 which suggests a diffusion-limited rate. The fast ET and PT chemistry is at-tributed to the delocalized electronic structure of [Co 13 C 2 (CO) 24 ] 4– . Electrochemical characterization of [Co 13 C 2 (CO) 24 ] 4– in the presence and absence of protons reveals ET kinetics and diffusion behavior similar to other small clusters such as nano-materials and fullerenes.

08 HYDROGEN↗
DOE OSTI2020

Competing ferro- and antiferromagnetic exchange drives shape-selective $\mathrm{Co_3O_4}$ nanomagnetism

We have synthesized three different shapes of Co 3 O 4 nanoparticles to investigate the relationships between the surface Co 2+ and Co 3+ bonding quantified by exploiting the known exposed surface planes, terminations, and coordiations of Co 3 O 4 nanoparticle spheres, cubes and plates. Subsequently this information is related to the unusual behaviour observed in the magnetism. The competition of exchange interactions at the surface provides the mechanism for different behaviours in the shapes. The cubes display weakened antiferromagnetic interactions in the form of a spin-flop that occurs at the surface, while the plates show distinct ferromagnetic behaviour due to the strong competition between the interactions. We elucidate the spin properties which are highly sensitive to bonding and crystal field environments. This work provides a new window into the mechanisms behind surface magnetism.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mn2Fe(CO)14 by Materials Project

(Mn(CO)5)2Fe(CO)4 crystallizes in the monoclinic C2/m space group. The structure is zero-dimensional and consists of four Fe(CO)4 clusters and eight Mn(CO)5 clusters. In two of the Fe(CO)4 clusters, Fe2+ is bonded in a square co-planar geometry to four C+1.57+ atoms. There is two shorter (1.82 Å) and two longer (1.83 Å) Fe–C bond length. There are two inequivalent C+1.57+ sites. In the first C+1.57+ site, C+1.57+ is bonded in a linear geometry to one Fe2+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.57+ site, C+1.57+ is bonded in a linear geometry to one Fe2+ and one O2- atom. The C–O bond length is 1.16 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.57+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.57+ atom. In two of the Fe(CO)4 clusters, Fe2+ is bonded in a square co-planar geometry to four equivalent C+1.57+ atoms. There is two shorter (1.82 Å) and two longer (1.83 Å) Fe–C bond length. C+1.57+ is bonded in a linear geometry to one Fe2+ and one O2- atom. The C–O bond length is 1.16 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.57+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.57+ atom. The O–C bond length is 1.16 Å. In four of the Mn(CO)5 clusters, Mn2+ is bonded in a square pyramidal geometry to five C+1.57+ atoms. There are a spread of Mn–C bond distances ranging from 1.81–1.87 Å. There are three inequivalent C+1.57+ sites. In the first C+1.57+ site, C+1.57+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.57+ site, C+1.57+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.57+ site, C+1.57+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.57+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.57+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.57+ atom. In four of the Mn(CO)5 clusters, Mn2+ is bonded in a square pyramidal geometry to five C+1.57+ atoms. There are a spread of Mn–C bond distances ranging from 1.82–1.87 Å. There are three inequivalent C+1.57+ sites. In the first C+1.57+ site, C+1.57+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.57+ site, C+1.57+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.57+ site, C+1.57+ is bonded in a linear geometry to one Mn2+ and one O2- atom. The C–O bond length is 1.16 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.57+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.57+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.57+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe4Si(CO)16 by Materials Project

(Fe(CO)4)4Si crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four silicon molecules and sixteen Fe(CO)4 clusters. In four of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There are a spread of Fe–C bond distances ranging from 1.77–1.81 Å. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In four of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There are a spread of Fe–C bond distances ranging from 1.76–1.82 Å. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In eight of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There is one shorter (1.77 Å) and three longer (1.80 Å) Fe–C bond length. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe4Ge(CO)16 by Materials Project

(Fe(CO)4)4Ge crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four germanium molecules and sixteen Fe(CO)4 clusters. In four of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There are a spread of Fe–C bond distances ranging from 1.77–1.82 Å. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In four of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There are a spread of Fe–C bond distances ranging from 1.77–1.81 Å. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In eight of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There is two shorter (1.79 Å) and two longer (1.82 Å) Fe–C bond length. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Fe4Sn(CO)16 by Materials Project

(Fe(CO)4)4Sn crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four 7440-31-5 molecules and sixteen Fe(CO)4 clusters. In four of the Fe(CO)4 clusters, Fe3+ is bonded in a see-saw-like geometry to four C1+ atoms. There is one shorter (1.77 Å) and three longer (1.81 Å) Fe–C bond length. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In four of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There are a spread of Fe–C bond distances ranging from 1.77–1.81 Å. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In eight of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted see-saw-like geometry to four C1+ atoms. There are a spread of Fe–C bond distances ranging from 1.78–1.81 Å. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Improved ELMv1-ECA simulations of zero-curtain periods and cold-season CH 4 and CO 2 emissions at Alaskan Arctic tundra sites

Field measurements have shown that cold-season methane (CH 4 ) and carbon dioxide (CO 2 ) emissions contribute a substantial portion to the annual net carbon emissions in permafrost regions. However, most earth system land models do not accurately reproduce cold-season CH 4 and CO 2 emissions, especially over the shoulder (i.e., thawing and freezing) seasons. Here we use the Energy Exascale Earth System Model (E3SM) land model version 1 (ELMv1-ECA) to tackle this challenge and fill the knowledge gap of how cold-season CH 4 and CO 2 emissions contribute to the annual totals at Alaska Arctic tundra sites. Specifically, we improved the ELMv1-ECA soil water phase-change scheme, environmental controls on microbial activity, and the methane module. Results demonstrate that both soil temperature and the duration of zero-curtain periods (i.e., the fall period when soil temperatures linger around 0°C) simulated by the updated ELMv1-ECA were greatly improved; e.g., the mean absolute error (MAE) in zero-curtain durations at 12 cm depth was reduced by 62 % on average. Furthermore, the MAEs of simulated cold-season carbon emissions at three tundra sites were improved by 72 % and 70 % on average for CH 4 and CO 2 , respectively. Overall, CH 4 emitted during the early cold season (September and October), which often includes most of the zero-curtain period in Arctic tundra, accounted for more than 50 % of the total emissions throughout the entire cold season (September to May) in the model, compared with around 49.4 % (43 %–58 %) in observations. From 1950 to 2017, both CO 2 emissions during the zero-curtain period and during the entire cold season showed increasing trends, for example, of 0.17 and 0.36 gC m -2 yr -1 at Atqasuk. This study highlights the importance of zero-curtain periods in facilitating cold-season CH 4 and CO 2 emissions from tundra ecosystems.

58 GEOSCIENCES↗
NASA NTRS1991

An ab initio study of Fe(CO)n, n = 1,5, and Cr(CO)6

Ab initio calculations have been performed for Cr(CO)6 and Fe(CO)n, n = 1,5. Basis sets of better than double zeta quality are used, and correlation is included using the modified coupler-pair functional method. The computed geometries and force constants are in reasonable agreement with experiment. The sequential bond dissociation energies of CO from Fe(CO)5 are estimated to be: 39, 31, 25, 22, and greater than 5 kcal/mol. It is noted that the first bond dissociation energy is relative to the singlet ground state of Fe(CO)5 and the lowest singlet state of Fe(CO)4, whereas the second is relative to the ground triplet states of Fe(CO)4 and Fe(CO)3. In addition, the binding energy for Fe-CO would be modified to 18 kcal/mol if dissociation occurred to the Fe(5F) excited state asymptote. The CO binding energies for Fe and Cr are found to be in poorer agreement with experiment than those found in a previous study on Ni(CO)4. The origins of this difference are discussed.

Barnes, Leslie A.↗
DOE OSTI2020

Materials Data on InCo3(CO)12 by Materials Project

In(Co(CO)4)3 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four indium molecules and twelve Co(CO)4 clusters. In each Co(CO)4 cluster, Co+1.67+ is bonded in a distorted trigonal pyramidal geometry to four C+1.33+ atoms. There are a spread of Co–C bond distances ranging from 1.76–1.78 Å. There are four inequivalent C+1.33+ sites. In the first C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.33+ site, C+1.33+ is bonded in a distorted single-bond geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.15 Å. In the fourth C+1.33+ site, C+1.33+ is bonded in a distorted linear geometry to one Co+1.67+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaCo(N2O3)4 by Materials Project

Na(Na(NO3)4)3(Co)4(N2)5(N5O6)2 crystallizes in the cubic P23 space group. The structure is zero-dimensional and consists of ten ammonia molecules, four cobalt molecules, one sodium molecule, one N5O6 cluster, and three Na(NO3)4 clusters. In the N5O6 cluster, there are two inequivalent N+2.50+ sites. In the first N+2.50+ site, N+2.50+ is bonded in a 2-coordinate geometry to two equivalent O2- atoms. Both N–O bond lengths are 2.11 Å. In the second N+2.50+ site, N+2.50+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All N–O bond lengths are 1.27 Å. O2- is bonded in a distorted single-bond geometry to two N+2.50+ atoms. In each Na(NO3)4 cluster, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.68 Å) and four longer (2.72 Å) Na–O bond lengths. There are two inequivalent N+2.50+ sites. In the first N+2.50+ site, N+2.50+ is bonded in a bent 120 degrees geometry to two equivalent O2- atoms. Both N–O bond lengths are 1.24 Å. In the second N+2.50+ site, N+2.50+ is bonded in a water-like geometry to two equivalent O2- atoms. Both N–O bond lengths are 1.37 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Na1+ and one N+2.50+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Na1+, one N+2.50+, and one O2- atom. The O–O bond length is 1.32 Å. In the third O2- site, O2- is bonded in a single-bond geometry to one O2- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Co2SnC8(ClO4)2 by Materials Project

(Co(CO)4)2SnCl2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four 7772-99-8 molecules and eight Co(CO)4 clusters. In four of the Co(CO)4 clusters, Co2+ is bonded in a trigonal pyramidal geometry to four C+1.25+ atoms. There are a spread of Co–C bond distances ranging from 1.78–1.80 Å. There are four inequivalent C+1.25+ sites. In the first C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In four of the Co(CO)4 clusters, Co2+ is bonded in a trigonal pyramidal geometry to four C+1.25+ atoms. There are a spread of Co–C bond distances ranging from 1.78–1.80 Å. There are four inequivalent C+1.25+ sites. In the first C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. In the second C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+1.25+ site, C+1.25+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.25+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Co4Ge(CO)13 by Materials Project

(Co(CO)3)3Co(CO)4Ge crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of six akos016035116 molecules, two germanium molecules, and two Co(CO)4 clusters. In each Co(CO)4 cluster, Co2+ is bonded in a trigonal pyramidal geometry to four C+1.08+ atoms. There is one shorter (1.77 Å) and three longer (1.78 Å) Co–C bond length. There are four inequivalent C+1.08+ sites. In the first C+1.08+ site, C+1.08+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C+1.08+ site, C+1.08+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. In the third C+1.08+ site, C+1.08+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. In the fourth C+1.08+ site, C+1.08+ is bonded in a linear geometry to one Co2+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C+1.08+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+1.08+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C+1.08+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C+1.08+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on FeC7(O2F)2 by Materials Project

Fe(CO)4C(CF)2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of sixteen fluoromethane molecules, eight methane molecules, and eight Fe(CO)4 clusters. In four of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted rectangular see-saw-like geometry to four C1+ atoms. There is one shorter (1.80 Å) and three longer (1.82 Å) Fe–C bond length. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. In the third C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. In the fourth C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In four of the Fe(CO)4 clusters, Fe3+ is bonded in a distorted rectangular see-saw-like geometry to four C1+ atoms. There is one shorter (1.80 Å) and three longer (1.82 Å) Fe–C bond length. There are four inequivalent C1+ sites. In the first C1+ site, C1+ is bonded in a distorted linear geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. In the second C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. In the third C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.15 Å. In the fourth C1+ site, C1+ is bonded in a distorted single-bond geometry to one Fe3+ and one O2- atom. The C–O bond length is 1.16 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one C1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one C1+ atom.

36 MATERIALS SCIENCE↗