SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
La1.0Ca2.0Mn2O7 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ca2+ is bonded in a 1-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.25–2.76 Å. La3+ is bonded to twelve O2- atoms to form LaO12 cuboctahedra that share corners with four equivalent LaO12 cuboctahedra, faces with four equivalent LaO12 cuboctahedra, and faces with eight equivalent MnO6 octahedra. There are eight shorter (2.69 Å) and four longer (2.74 Å) La–O bond lengths. Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with five equivalent MnO6 octahedra and faces with four equivalent LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–7°. There are a spread of Mn–O bond distances ranging from 1.90–1.99 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four equivalent La3+ and two equivalent Mn+3.50+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to five equivalent Ca2+ and one Mn+3.50+ atom. In the third O2- site, O2- is bonded to two equivalent Ca2+, two equivalent La3+, and two equivalent Mn+3.50+ atoms to form a mixture of distorted corner, edge, and face-sharing OCa2La2Mn2 octahedra. The corner-sharing octahedra tilt angles range from 0–61°.
Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations