Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Np”

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.

At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Np3HF12 by Materials Project

Np3HF12 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Np+3.67+ sites. In the first Np+3.67+ site, Np+3.67+ is bonded in a 7-coordinate geometry to one H1+ and seven F1- atoms. The Np–H bond length is 2.74 Å. There are a spread of Np–F bond distances ranging from 2.18–2.29 Å. In the second Np+3.67+ site, Np+3.67+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Np–F bond distances ranging from 2.25–2.52 Å. In the third Np+3.67+ site, Np+3.67+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Np–F bond distances ranging from 2.23–2.31 Å. In the fourth Np+3.67+ site, Np+3.67+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Np–F bond distances ranging from 2.24–2.31 Å. In the fifth Np+3.67+ site, Np+3.67+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Np–F bond distances ranging from 2.25–2.51 Å. In the sixth Np+3.67+ site, Np+3.67+ is bonded in a 8-coordinate geometry to one H1+ and seven F1- atoms. The Np–H bond length is 2.05 Å. There are a spread of Np–F bond distances ranging from 2.20–2.32 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one Np+3.67+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one Np+3.67+ atom. There are twenty-four inequivalent F1- sites. In the first F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the second F1- site, F1- is bonded in a linear geometry to two Np+3.67+ atoms. In the third F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the fourth F1- site, F1- is bonded in a distorted linear geometry to two Np+3.67+ atoms. In the fifth F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the sixth F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the seventh F1- site, F1- is bonded in a distorted bent 120 degrees geometry to two Np+3.67+ atoms. In the eighth F1- site, F1- is bonded in a linear geometry to two Np+3.67+ atoms. In the ninth F1- site, F1- is bonded in a linear geometry to two Np+3.67+ atoms. In the tenth F1- site, F1- is bonded in a linear geometry to two Np+3.67+ atoms. In the eleventh F1- site, F1- is bonded in a bent 120 degrees geometry to two Np+3.67+ atoms. In the twelfth F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the thirteenth F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the fourteenth F1- site, F1- is bonded in a distorted linear geometry to two Np+3.67+ atoms. In the fifteenth F1- site, F1- is bonded in a bent 120 degrees geometry to two Np+3.67+ atoms. In the sixteenth F1- site, F1- is bonded in a linear geometry to two Np+3.67+ atoms. In the seventeenth F1- site, F1- is bonded in a bent 120 degrees geometry to two Np+3.67+ atoms. In the eighteenth F1- site, F1- is bonded in a 2-coordinate geometry to two Np+3.67+ atoms. In the nineteenth F1- site, F1- is bonded in a bent 120 degrees geometry to two Np+3.67+ atoms. In the twentieth F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the twenty-first F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the twenty-second F1- site, F1- is bonded in a bent 120 degrees geometry to two Np+3.67+ atoms. In the twenty-third F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+3.67+ atoms. In the twenty-fourth F1- site, F1- is bonded in a distorted bent 120 degrees geometry to two Np+3.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np3S5 by Materials Project

Np3S5 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are eight inequivalent Np+3.33+ sites. In the first Np+3.33+ site, Np+3.33+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Np–S bond distances ranging from 2.78–2.99 Å. In the second Np+3.33+ site, Np+3.33+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Np–S bond distances ranging from 2.78–2.99 Å. In the third Np+3.33+ site, Np+3.33+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Np–S bond distances ranging from 2.78–2.99 Å. In the fourth Np+3.33+ site, Np+3.33+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Np–S bond distances ranging from 2.77–3.00 Å. In the fifth Np+3.33+ site, Np+3.33+ is bonded to seven S2- atoms to form distorted edge-sharing NpS7 pentagonal bipyramids. There are a spread of Np–S bond distances ranging from 2.66–2.82 Å. In the sixth Np+3.33+ site, Np+3.33+ is bonded to seven S2- atoms to form distorted edge-sharing NpS7 pentagonal bipyramids. There are a spread of Np–S bond distances ranging from 2.65–2.83 Å. In the seventh Np+3.33+ site, Np+3.33+ is bonded to seven S2- atoms to form distorted edge-sharing NpS7 pentagonal bipyramids. There are a spread of Np–S bond distances ranging from 2.64–2.82 Å. In the eighth Np+3.33+ site, Np+3.33+ is bonded to seven S2- atoms to form distorted edge-sharing NpS7 pentagonal bipyramids. There are a spread of Np–S bond distances ranging from 2.64–2.83 Å. There are sixteen inequivalent S2- sites. In the first S2- site, S2- is bonded to five Np+3.33+ atoms to form distorted SNp5 trigonal bipyramids that share corners with six SNp5 square pyramids, corners with four equivalent SNp5 trigonal bipyramids, corners with two equivalent SNp4 trigonal pyramids, edges with six SNp5 square pyramids, and edges with two equivalent SNp4 trigonal pyramids. In the second S2- site, S2- is bonded to five Np+3.33+ atoms to form distorted SNp5 trigonal bipyramids that share corners with six SNp5 square pyramids, corners with four equivalent SNp5 trigonal bipyramids, corners with four SNp4 trigonal pyramids, edges with six SNp5 square pyramids, and edges with two equivalent SNp4 trigonal pyramids. In the third S2- site, S2- is bonded to five Np+3.33+ atoms to form distorted SNp5 trigonal bipyramids that share corners with six SNp5 square pyramids, corners with four equivalent SNp5 trigonal bipyramids, corners with four SNp4 trigonal pyramids, edges with six SNp5 square pyramids, and edges with four SNp4 trigonal pyramids. In the fourth S2- site, S2- is bonded to five Np+3.33+ atoms to form distorted SNp5 trigonal bipyramids that share corners with six SNp5 square pyramids, corners with four equivalent SNp5 trigonal bipyramids, corners with two equivalent SNp4 trigonal pyramids, edges with six SNp5 square pyramids, and edges with four SNp4 trigonal pyramids. In the fifth S2- site, S2- is bonded to five Np+3.33+ atoms to form SNp5 square pyramids that share corners with four SNp5 square pyramids, corners with five SNp5 trigonal bipyramids, corners with eight SNp4 trigonal pyramids, edges with three SNp5 square pyramids, edges with two SNp5 trigonal bipyramids, and a faceface with one SNp5 square pyramid. In the sixth S2- site, S2- is bonded to five Np+3.33+ atoms to form SNp5 square pyramids that share corners with four SNp5 square pyramids, corners with five SNp5 trigonal bipyramids, corners with six SNp4 trigonal pyramids, edges with three SNp5 square pyramids, edges with two SNp5 trigonal bipyramids, edges with two equivalent SNp4 trigonal pyramids, and a faceface with one SNp5 square pyramid. In the seventh S2- site, S2- is bonded to five Np+3.33+ atoms to form SNp5 square pyramids that share corners with four SNp5 square pyramids, corners with five SNp5 trigonal bipyramids, corners with six SNp4 trigonal pyramids, edges with three SNp5 square pyramids, edges with two SNp5 trigonal bipyramids, edges with two equivalent SNp4 trigonal pyramids, and a faceface with one SNp5 square pyramid. In the eighth S2- site, S2- is bonded to five Np+3.33+ atoms to form SNp5 square pyramids that share corners with four SNp5 square pyramids, corners with five SNp5 trigonal bipyramids, corners with four SNp4 trigonal pyramids, edges with three SNp5 square pyramids, edges with two SNp5 trigonal bipyramids, edges with two equivalent SNp4 trigonal pyramids, and a faceface with one SNp5 square pyramid. In the ninth S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to four Np+3.33+ atoms. In the tenth S2- site, S2- is bonded to four Np+3.33+ atoms to form distorted SNp4 trigonal pyramids that share corners with six SNp5 square pyramids, corners with two SNp5 trigonal bipyramids, corners with four SNp4 trigonal pyramids, edges with three SNp5 square pyramids, edges with two SNp5 trigonal bipyramids, and an edgeedge with one SNp4 trigonal pyramid. In the eleventh S2- site, S2- is bonded to four Np+3.33+ atoms to form distorted SNp4 trigonal pyramids that share corners with six SNp5 square pyramids, corners with two SNp5 trigonal bipyramids, corners with six SNp4 trigonal pyramids, edges with three SNp5 square pyramids, edges with two SNp5 trigonal bipyramids, and an edgeedge with one SNp4 trigonal pyramid. In the twelfth S2- site, S2- is bonded to four Np+3.33+ atoms to form distorted SNp4 trigonal pyramids that share corners with six SNp5 square pyramids, corners with two SNp5 trigonal bipyramids, corners with four SNp4 trigonal pyramids, edges with three SNp5 square pyramids, and edges with two SNp5 trigonal bipyramids. In the thirteenth S2- site, S2- is bonded to five Np+3.33+ atoms to form distorted SNp5 square pyramids that share corners with eight SNp5 square pyramids, a cornercorner with one SNp5 trigonal bipyramid, corners with four SNp4 trigonal pyramids, an edgeedge with one SNp5 square pyramid, edges with four SNp5 trigonal bipyramids, edges with two equivalent SNp4 trigonal pyramids, and a faceface with one SNp5 square pyramid. In the fourteenth S2- site, S2- is bonded to five Np+3.33+ atoms to form distorted SNp5 square pyramids that share corners with eight SNp5 square pyramids, a cornercorner with one SNp5 trigonal bipyramid, corners with two equivalent SNp4 trigonal pyramids, an edgeedge with one SNp5 square pyramid, edges with four SNp5 trigonal bipyramids, edges with two equivalent SNp4 trigonal pyramids, and a faceface with one SNp5 square pyramid. In the fifteenth S2- site, S2- is bonded to five Np+3.33+ atoms to form distorted SNp5 square pyramids that share corners with eight SNp5 square pyramids, a cornercorner with one SNp5 trigonal bipyramid, corners with two equivalent SNp4 trigonal pyramids, an edgeedge with one SNp5 square pyramid, edges with four SNp5 trigonal bipyramids, edges with four SNp4 trigonal pyramids, and a faceface with one SNp5 square pyramid. In the sixteenth S2- site, S2- is bonded to five Np+3.33+ atoms to form distorted SNp5 square pyramids that share corners with eight SNp5 square pyramids, a cornercorner with one SNp5 trigonal bipyramid, corners with four SNp4 trigonal pyramids, an edgeedge with one SNp5 square pyramid, edges with four SNp5 trigonal bipyramids, edges with four SNp4 trigonal pyramids, and a faceface with one SNp5 square pyramid.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np3OF12 by Materials Project

Np3OF12 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Np+4.67+ sites. In the first Np+4.67+ site, Np+4.67+ is bonded in a 1-coordinate geometry to one O2- and seven F1- atoms. The Np–O bond length is 1.80 Å. There are a spread of Np–F bond distances ranging from 2.22–2.35 Å. In the second Np+4.67+ site, Np+4.67+ is bonded in a 1-coordinate geometry to one O2- and seven F1- atoms. The Np–O bond length is 1.79 Å. There are a spread of Np–F bond distances ranging from 2.20–2.39 Å. In the third Np+4.67+ site, Np+4.67+ is bonded in a 9-coordinate geometry to nine F1- atoms. There are a spread of Np–F bond distances ranging from 2.21–2.46 Å. In the fourth Np+4.67+ site, Np+4.67+ is bonded in a 8-coordinate geometry to eight F1- atoms. There are a spread of Np–F bond distances ranging from 2.18–2.34 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Np+4.67+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one Np+4.67+ atom. There are fourteen inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Np+4.67+ atoms. In the second F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Np+4.67+ atoms. In the third F1- site, F1- is bonded in a linear geometry to two Np+4.67+ atoms. In the fourth F1- site, F1- is bonded in a bent 120 degrees geometry to two equivalent Np+4.67+ atoms. In the fifth F1- site, F1- is bonded in a bent 150 degrees geometry to two equivalent Np+4.67+ atoms. In the sixth F1- site, F1- is bonded in a distorted water-like geometry to two equivalent Np+4.67+ atoms. In the seventh F1- site, F1- is bonded in a bent 120 degrees geometry to two Np+4.67+ atoms. In the eighth F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+4.67+ atoms. In the ninth F1- site, F1- is bonded in a 2-coordinate geometry to two Np+4.67+ atoms. In the tenth F1- site, F1- is bonded in a linear geometry to two Np+4.67+ atoms. In the eleventh F1- site, F1- is bonded in a bent 150 degrees geometry to two Np+4.67+ atoms. In the twelfth F1- site, F1- is bonded in a bent 120 degrees geometry to two Np+4.67+ atoms. In the thirteenth F1- site, F1- is bonded in a distorted bent 150 degrees geometry to two Np+4.67+ atoms. In the fourteenth F1- site, F1- is bonded in a distorted linear geometry to two Np+4.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np2InPt2 by Materials Project

Np2Pt2In crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are four inequivalent Np sites. In the first Np site, Np is bonded in a 6-coordinate geometry to six Pt and four In atoms. There are a spread of Np–Pt bond distances ranging from 2.84–2.99 Å. All Np–In bond lengths are 3.40 Å. In the second Np site, Np is bonded in a 6-coordinate geometry to six Pt and four In atoms. There are a spread of Np–Pt bond distances ranging from 2.81–2.98 Å. All Np–In bond lengths are 3.39 Å. In the third Np site, Np is bonded in a 6-coordinate geometry to six Pt and four In atoms. There are a spread of Np–Pt bond distances ranging from 2.84–2.99 Å. All Np–In bond lengths are 3.39 Å. In the fourth Np site, Np is bonded in a 6-coordinate geometry to six Pt and four In atoms. There are a spread of Np–Pt bond distances ranging from 2.81–2.96 Å. There are two shorter (3.39 Å) and two longer (3.40 Å) Np–In bond lengths. There are four inequivalent Pt sites. In the first Pt site, Pt is bonded in a 9-coordinate geometry to six Np and two In atoms. There are one shorter (2.99 Å) and one longer (3.03 Å) Pt–In bond lengths. In the second Pt site, Pt is bonded in a 9-coordinate geometry to six Np, one Pt, and two In atoms. The Pt–Pt bond length is 2.89 Å. There are one shorter (3.01 Å) and one longer (3.03 Å) Pt–In bond lengths. In the third Pt site, Pt is bonded in a 9-coordinate geometry to six Np, one Pt, and two In atoms. There are one shorter (2.98 Å) and one longer (3.01 Å) Pt–In bond lengths. In the fourth Pt site, Pt is bonded in a 9-coordinate geometry to six Np and two In atoms. There are one shorter (2.97 Å) and one longer (3.02 Å) Pt–In bond lengths. There are two inequivalent In sites. In the first In site, In is bonded to eight Np and four Pt atoms to form a mixture of distorted corner and face-sharing InNp8Pt4 cuboctahedra. In the second In site, In is bonded to eight Np and four Pt atoms to form a mixture of distorted corner and face-sharing InNp8Pt4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np2Cr3(NO4)4 by Materials Project

Np2Cr3O16(N2)2 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of eight ammonia molecules and one Np2Cr3O16 sheet oriented in the (0, 1, 1) direction. In the Np2Cr3O16 sheet, there are two inequivalent Np+6.50+ sites. In the first Np+6.50+ site, Np+6.50+ is bonded to seven O2- atoms to form distorted NpO7 pentagonal bipyramids that share corners with three CrO4 tetrahedra, an edgeedge with one NpO7 pentagonal bipyramid, and an edgeedge with one CrO4 tetrahedra. There are a spread of Np–O bond distances ranging from 1.77–2.45 Å. In the second Np+6.50+ site, Np+6.50+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Np–O bond distances ranging from 1.77–2.63 Å. There are three inequivalent Cr5+ sites. In the first Cr5+ site, Cr5+ is bonded to four O2- atoms to form CrO4 tetrahedra that share a cornercorner with one NpO7 pentagonal bipyramid and an edgeedge with one NpO7 pentagonal bipyramid. There are a spread of Cr–O bond distances ranging from 1.60–1.78 Å. In the second Cr5+ site, Cr5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Cr–O bond distances ranging from 1.60–1.76 Å. In the third Cr5+ site, Cr5+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with two equivalent NpO7 pentagonal bipyramids. There are a spread of Cr–O bond distances ranging from 1.59–1.74 Å. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Np+6.50+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one Np+6.50+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one Np+6.50+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one Np+6.50+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Np+6.50+ and one Cr5+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to two Np+6.50+ and one Cr5+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one Cr5+ atom. In the eighth O2- site, O2- is bonded in a single-bond geometry to one Cr5+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Np+6.50+ and one Cr5+ atom. In the tenth O2- site, O2- is bonded in a linear geometry to one Np+6.50+ and one Cr5+ atom. In the eleventh O2- site, O2- is bonded in a single-bond geometry to one Cr5+ atom. In the twelfth O2- site, O2- is bonded in a single-bond geometry to one Cr5+ atom. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to two Np+6.50+ and one Cr5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted single-bond geometry to one Np+6.50+ and one Cr5+ atom. In the fifteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Np+6.50+ and one Cr5+ atom. In the sixteenth O2- site, O2- is bonded in a single-bond geometry to one Cr5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpFe(OF2)3 by Materials Project

NpFe(OF2)3 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are two inequivalent Np sites. In the first Np site, Np is bonded to one O and six F atoms to form distorted NpOF6 pentagonal bipyramids that share corners with four equivalent FeO2F4 octahedra. The corner-sharing octahedra tilt angles range from 33–37°. The Np–O bond length is 1.80 Å. There are a spread of Np–F bond distances ranging from 2.04–2.18 Å. In the second Np site, Np is bonded to one O and six F atoms to form distorted NpOF6 pentagonal bipyramids that share corners with four equivalent FeO2F4 octahedra. The corner-sharing octahedra tilt angles range from 33–37°. The Np–O bond length is 1.80 Å. There are a spread of Np–F bond distances ranging from 2.04–2.18 Å. Fe is bonded to two O and four F atoms to form FeO2F4 octahedra that share corners with four NpOF6 pentagonal bipyramids. Both Fe–O bond lengths are 1.67 Å. There are two shorter (2.07 Å) and two longer (2.20 Å) Fe–F bond lengths. There are four inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Np atom. In the second O site, O is bonded in a single-bond geometry to one Fe atom. In the third O site, O is bonded in a single-bond geometry to one Np atom. In the fourth O site, O is bonded in a single-bond geometry to one Fe atom. There are six inequivalent F sites. In the first F site, F is bonded in a bent 150 degrees geometry to one Np and one Fe atom. In the second F site, F is bonded in a bent 150 degrees geometry to one Np and one Fe atom. In the third F site, F is bonded in a bent 150 degrees geometry to one Np and one Fe atom. In the fourth F site, F is bonded in a single-bond geometry to one Np atom. In the fifth F site, F is bonded in a bent 150 degrees geometry to one Np and one Fe atom. In the sixth F site, F is bonded in a single-bond geometry to one Np atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CaNp by Materials Project

CaNp is alpha La-derived structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Ca sites. In the first Ca site, Ca is bonded to six equivalent Ca and six equivalent Np atoms to form CaCa6Np6 cuboctahedra that share corners with twelve CaCa6Np6 cuboctahedra, edges with twelve CaCa6Np6 cuboctahedra, edges with twelve equivalent NpCa6Np6 cuboctahedra, faces with six equivalent CaCa6Np6 cuboctahedra, and faces with twelve equivalent NpCa6Np6 cuboctahedra. All Ca–Ca bond lengths are 3.39 Å. All Ca–Np bond lengths are 3.69 Å. In the second Ca site, Ca is bonded to six equivalent Ca and six Np atoms to form CaCa6Np6 cuboctahedra that share corners with five equivalent NpCa6Np10 cuboctahedra, corners with twelve CaCa6Np6 cuboctahedra, edges with ten NpCa6Np6 cuboctahedra, edges with twelve CaCa6Np6 cuboctahedra, faces with six equivalent CaCa6Np6 cuboctahedra, and faces with fifteen NpCa6Np6 cuboctahedra. All Ca–Ca bond lengths are 3.39 Å. All Ca–Np bond lengths are 3.69 Å. In the third Ca site, Ca is bonded to six equivalent Ca and six Np atoms to form CaCa6Np6 cuboctahedra that share corners with five equivalent NpCa6Np10 cuboctahedra, corners with twelve CaCa6Np6 cuboctahedra, edges with ten NpCa6Np6 cuboctahedra, edges with twelve CaCa6Np6 cuboctahedra, faces with six equivalent CaCa6Np6 cuboctahedra, and faces with fifteen NpCa6Np6 cuboctahedra. All Ca–Ca bond lengths are 3.39 Å. All Ca–Np bond lengths are 3.69 Å. There are two inequivalent Np sites. In the first Np site, Np is bonded to six Ca and six equivalent Np atoms to form NpCa6Np6 cuboctahedra that share corners with twelve NpCa6Np6 cuboctahedra, edges with twelve CaCa6Np6 cuboctahedra, edges with twelve NpCa6Np6 cuboctahedra, faces with six equivalent NpCa6Np6 cuboctahedra, and faces with twelve CaCa6Np6 cuboctahedra. All Np–Np bond lengths are 3.39 Å. In the second Np site, Np is bonded to six Ca and ten equivalent Np atoms to form NpCa6Np10 cuboctahedra that share corners with ten CaCa6Np6 cuboctahedra, corners with twelve NpCa6Np6 cuboctahedra, edges with eight CaCa6Np6 cuboctahedra, edges with sixteen NpCa6Np6 cuboctahedra, faces with sixteen equivalent NpCa6Np10 cuboctahedra, and faces with eighteen CaCa6Np6 cuboctahedra. There are a spread of Np–Np bond distances ranging from 3.39–6.78 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NpNi(OF2)3 by Materials Project

NpNi(OF2)3 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are two inequivalent Np sites. In the first Np site, Np is bonded in a 7-coordinate geometry to one O and six F atoms. The Np–O bond length is 1.81 Å. There are a spread of Np–F bond distances ranging from 2.06–2.18 Å. In the second Np site, Np is bonded in a 7-coordinate geometry to one O and six F atoms. The Np–O bond length is 1.81 Å. There are two shorter (2.06 Å) and four longer (2.18 Å) Np–F bond lengths. Ni is bonded in an octahedral geometry to two O and four F atoms. Both Ni–O bond lengths are 1.85 Å. There are a spread of Ni–F bond distances ranging from 2.09–2.11 Å. There are four inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Ni atom. In the second O site, O is bonded in a single-bond geometry to one Ni atom. In the third O site, O is bonded in a single-bond geometry to one Np atom. In the fourth O site, O is bonded in a single-bond geometry to one Np atom. There are six inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one Np atom. In the second F site, F is bonded in a bent 150 degrees geometry to one Np and one Ni atom. In the third F site, F is bonded in a bent 150 degrees geometry to one Np and one Ni atom. In the fourth F site, F is bonded in a single-bond geometry to one Np atom. In the fifth F site, F is bonded in a bent 150 degrees geometry to one Np and one Ni atom. In the sixth F site, F is bonded in a bent 150 degrees geometry to one Np and one Ni atom.

36 MATERIALS SCIENCE↗
DOE OSTI2021

The crystal and coordination chemistry of neptunium in all its oxidation states: An expanded structural hierarchy of neptunium compounds

We report structures of 388 neptunium-bearing crystal structures are sorted into an expanded structural hierarchy and examined. The majority of structures contain Np(V) (149), Np(VI) (99), or Np(IV) (91) whereas structures containing Np(II), Np(III), Np(VII), or more than one oxidation state are rare. Coordination geometry of Np(V) and Np(VI) compounds is dominated by the approximately linear neptunyl cation. Actinyl–actinyl interactions (AAIs) are most prevalent in Np(V) compounds and are observed in 48% of these extended structures. Prismatic coordination geometries are commonly observed in Np(IV) compounds. Np(III) organometallic complexes display a variety of coordination modes. Coordination chemistry of Np(VII) compounds is dominated by the tetra-oxido core. Updated average bond length values are provided for Np(IV), Np(V), Np(VI), and Np(VII) compounds and updated bond valence parameters for Np(IV) are reported. A graphical notation system for neptunyl structures coordinated by organic ligands was developed to facilitate discussion and identify similarities between neptunyl compounds coordinated by oxyanions and neptunyl compounds coordinated by organic ligands.

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

Materials Data on Np2Co17 by Materials Project

Np2Co17 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Np sites. In the first Np site, Np is bonded in a 12-coordinate geometry to eighteen Co atoms. There are a spread of Np–Co bond distances ranging from 2.80–3.16 Å. In the second Np site, Np is bonded in a 2-coordinate geometry to twenty Co atoms. There are a spread of Np–Co bond distances ranging from 2.75–3.05 Å. There are eight inequivalent Co sites. In the first Co site, Co is bonded in a 2-coordinate geometry to one Np and thirteen Co atoms. There are a spread of Co–Co bond distances ranging from 2.35–2.67 Å. In the second Co site, Co is bonded to two equivalent Np and ten Co atoms to form CoNp2Co10 cuboctahedra that share corners with fourteen CoNp2Co10 cuboctahedra, edges with six CoNp3Co9 cuboctahedra, and faces with ten CoNp2Co10 cuboctahedra. There are four shorter (2.35 Å) and four longer (2.36 Å) Co–Co bond lengths. In the third Co site, Co is bonded to two equivalent Np and ten Co atoms to form CoNp2Co10 cuboctahedra that share corners with fourteen CoNp2Co10 cuboctahedra, edges with six CoNp3Co9 cuboctahedra, and faces with ten CoNp2Co10 cuboctahedra. There are four shorter (2.35 Å) and four longer (2.36 Å) Co–Co bond lengths. In the fourth Co site, Co is bonded in a 12-coordinate geometry to two Np and ten Co atoms. There are a spread of Co–Co bond distances ranging from 2.28–2.51 Å. In the fifth Co site, Co is bonded in a 12-coordinate geometry to two Np and ten Co atoms. There are a spread of Co–Co bond distances ranging from 2.28–2.51 Å. In the sixth Co site, Co is bonded in a 12-coordinate geometry to two Np and ten Co atoms. There are two shorter (2.41 Å) and two longer (2.46 Å) Co–Co bond lengths. In the seventh Co site, Co is bonded to three Np and nine Co atoms to form a mixture of distorted face, edge, and corner-sharing CoNp3Co9 cuboctahedra. Both Co–Co bond lengths are 2.34 Å. In the eighth Co site, Co is bonded to three Np and nine Co atoms to form a mixture of distorted face, edge, and corner-sharing CoNp3Co9 cuboctahedra.

36 MATERIALS SCIENCE↗
NASA NTRS1999

Three Paradigms of Lunar Regolith Evolution

Integration of diverse datasets on the Moon may render some paradigms of lunar science either better-defended or vulnerable. We will consider three paradigms commonly used for understanding the processes of lunar regolith evolution in light of new and accumulated data. Our premise is that all data-sets should converge to a single interpretation if a concept or model is to be accepted as a paradigm. If a convergence is lacking, the paradigm needs fresh scrutiny. SteadyState: Lunar regolith evolution is currently understood in terms of comminution, agglutination, and replenishment as described by McKay and coworkers). Briefly, the model envisages continued micrometeoritic bombardment to comminute exposed soil particles to finer sizes while continued agglutination consumes finer sizes to produce larger constructional particles. Eventually, a balance between these two opposing processes achieves a steady state; soils at steady state maintain their mean grain size (M(sub z)). Episodic higher-energy impacts excavate fresh coarse material from below the soil cover, disturb the steady state, and restart the process to achieve a new steady state. It follows that the thickness of the regolith at any site would control the frequency of replenishment; indeed, the thickness of the regolith at Apollo landing sites was predicted by McKay et al. from the average M(sub z) of local soils. However, replenishment may come also from disintegrating boulders and cobbles at the lunar surface, and rates of comminution and agglutination may depend on the properties of target material. Regression between M(sub z) and I(sub s)/Fe(sup 0) (a measure of maturity or total surface exposure) of Apollo soils at different sites shows the following relations and estimated M(sub z) at a high maturity of I(sub s)/Fe(sup 0)= 100. It is possible that Apollo 12 and 15 sites have the thickest regolith and the Apollo 16 site has the thinnest. It is also possible that Apollo 12 and 15 basalts are comminuted faster than Apollo 16 highland rocks and Apollo 14 and 17 soils are products of mixed parentage. If a soil becomes continually finer as it matures until agglutination catches up, and if comminution is differential-dependent on the physical properties of the constituents, then the composition of the bulk soil has to match the composition of some "fulcrum" grain size fraction, say X Grain size fractions >X and <X will complement each other; their mass balance is the bulk soil. It appears that the 10-20-micron size fraction may be the fulcrum. In general, trace-element chemistry and IR reflectance spectra of this size fraction are closest to that of the bulk soil, regardless of maturity that is surprising. Disaggregated products of regolith breccias may also show similar relationships. If the 10-20 gm is the fulcrum (i.e., X as above) for many soil properties (e.g., major element composition, FMR, solar-wind-implanted elements), then this may be the ultimate mean grain size of lunar soils at steady state. However, different properties of soils may find steady states at different grain size fractions. The steady state of solar-wind-implanted elements, on the other hand, will climb up the grain-size scale as agglutinates transfer surface-correlated components into volume correlated components until a saturation level is reached or the rates of replenishment and implantation become equal. The same will be the case with vapor-deposited reduced metals as they too are incorporated inside constructional particles. Properties that are directly affected by soil-maturation processes will thus have different pathways of achieving steady states. Maturity, i.e., cumulative surface exposure, of lunar soils is best quantified by the amount of nanophase superparamagnetic Fe(sup 0) (np-Fe(sup 0)) normalized to Fe content (=I(sub s)/Fe(sup 0). The majority consensus (paradigm?) for the production of np-Fe(sup 0) is associated with the production of agglutinates. Because large doses of solar-wind H are implanted in all lunar soils upon exposure, any melting (e.g., during agglutinate production) triggers a chemical reduction of Fe-bearing minerals resulting in np-Fe(sup 0) production. The quantity of np-Fe(sup 0) is thus dependent on melting events, (i.e., exposure), and limited by the Fe content of the soil. All freshly produced np-Fe(sup 0) resides in agglutinitic glass, as new TEM images show. Apparently, the correction procedure developed by Lucey et al. to estimate the Fe content of the lunar surface from IR-reflectance spectra depends on accepting the above. However, the process of producing np-Fe(sup 0) may be physical rather than chemical. All np-Fe(sup 0) could be deposits from a vapor produced by micrometeoritic impact on lunar soils. If metal-O bonds in target phases are broken, O being "most volatile" will escape leaving an O-deficient vapor to facilitate the production of np-Fe(sup 0). If so, the quantity of np-Fe(sup 0) is dependent on the vaporizing events, (i.e., exposure), and limited by the efficiency of breaking metal-O bonds and the escape of 0. To the extent that strengths of metal-O bonds are dependent on the local crystal field, production of np-Fe(sup 0) may be limited by the mineral composition of target soils and not by their total Fe content. According to this model, vapor-deposited np-Fe(sup 0) should be found at any retentive sites on lunar soil grains. Indeed, TEM images show np-Fe(sup 0) on plagioclase and ilmenite. Incorporation of such pre-irradiated np-Fe(sup 0)-bearing grains into agglutinates may account for eventual increased emplacement of np-Fe(sup 0) in agglutinates. Such a paradigm shift in understanding the origin of np-Fe(sup 0) will raise questions ranging from the unquestionable use of Is/FeO as the universal maturity parameter of lunar soils to global elemental maps of the Moon from remote-sensing data. Additional information is contained in the original.

Basu, A.↗
DOE OSTI2021

Electrochemical Manipulation and Radiolytic Evaluation of Organic Phase Neptunium

Presentation for Seed LDRD proposal presentation: This Seed LDRD research proposes to test an innovative approach to precisely control the oxidation state distribution of neptunium (Np) under used nuclear fuel (UNF) reprocessing conditions using novel electrochemical methods. Current UNF reprocessing technologies are not financially viable in the US, requiring significant scientific and technological innovation to improve cost efficiency. Reducing the number of process cycles is one avenue for increasing cost efficiency, of which resolving the challenge associated with isolating Np is critical. Under envisioned process conditions, Np is present in a mixture of extractable (Np(IV) and Np(VI)) and inextractable (Np(V)) oxidation states, the distribution of which is dependent on several factors, including ionizing radiation dose, that change throughout a reprocessing scheme. Consequently, Np unintentionally partitions into various UNF reprocessing phases and product streams, ultimately increasing the number of process cycles to isolate UNF components. Here, we propose to employ novel, high surface area, optically transparent, Ligand Modified tin-doped indium oxide Electrodes (LMES). These LMEs bind Np, and therefore enable concurrent generation and spectroscopic characterization of Np oxidation states in organic solutions. These proof-of-concept experiments will: (i) facilitate optimization of the proposed electrochemical system conditions for Np oxidation state manipulation; (ii) identify the accessible electrochemical window for Np complexes in the organic phase; (iii) report characteristic optical spectra for each accessible complexed Np oxidation state; and (iv) determine the lifetime and partitioning of a given atypical Np oxidation state in the organic phase in the presence and absence of ionizing radiation fields. The data gathered by this Seed LDRD will provide support for the design of an electrochemical process concept for the precise manipulation of Np oxidation states in UNF reprocessing solvent systems, with the intention of providing advanced control over Np mass transfer, and thus greater process efficiency and economy.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2020

Materials Data on Np2InRh2 by Materials Project

Np2Rh2In crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are three inequivalent Np sites. In the first Np site, Np is bonded in a 6-coordinate geometry to six Rh atoms. There are a spread of Np–Rh bond distances ranging from 2.73–2.92 Å. In the second Np site, Np is bonded in a 6-coordinate geometry to six Rh atoms. There are two shorter (2.72 Å) and four longer (2.91 Å) Np–Rh bond lengths. In the third Np site, Np is bonded in a 6-coordinate geometry to six Rh atoms. There are two shorter (2.72 Å) and four longer (2.91 Å) Np–Rh bond lengths. There are three inequivalent Rh sites. In the first Rh site, Rh is bonded in a 8-coordinate geometry to six Np and two equivalent In atoms. There are one shorter (2.98 Å) and one longer (2.99 Å) Rh–In bond lengths. In the second Rh site, Rh is bonded in a 8-coordinate geometry to six Np and two equivalent In atoms. Both Rh–In bond lengths are 2.98 Å. In the third Rh site, Rh is bonded in a 8-coordinate geometry to six Np and two equivalent In atoms. Both Rh–In bond lengths are 2.99 Å. In is bonded in a 4-coordinate geometry to four Rh atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgNp3 by Materials Project

MgNp3 is alpha La-derived structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Mg is bonded to twelve Np atoms to form MgNp12 cuboctahedra that share corners with four equivalent MgNp12 cuboctahedra, corners with eight equivalent NpMg4Np8 cuboctahedra, edges with eight equivalent MgNp12 cuboctahedra, edges with sixteen equivalent NpMg4Np8 cuboctahedra, faces with four equivalent MgNp12 cuboctahedra, and faces with fourteen NpMg4Np8 cuboctahedra. There are eight shorter (3.06 Å) and four longer (3.10 Å) Mg–Np bond lengths. There are two inequivalent Np sites. In the first Np site, Np is bonded to four equivalent Mg and eight equivalent Np atoms to form NpMg4Np8 cuboctahedra that share corners with four equivalent NpMg4Np8 cuboctahedra, corners with eight equivalent MgNp12 cuboctahedra, edges with twenty-four NpMg4Np8 cuboctahedra, faces with six equivalent MgNp12 cuboctahedra, and faces with twelve NpMg4Np8 cuboctahedra. All Np–Np bond lengths are 3.06 Å. In the second Np site, Np is bonded to four equivalent Mg and eight Np atoms to form NpMg4Np8 cuboctahedra that share corners with twelve equivalent NpMg4Np8 cuboctahedra, edges with eight equivalent MgNp12 cuboctahedra, edges with sixteen NpMg4Np8 cuboctahedra, faces with four equivalent MgNp12 cuboctahedra, and faces with fourteen NpMg4Np8 cuboctahedra. All Np–Np bond lengths are 3.10 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Synthesis and Reactivity of Heteroleptic U 4+ Alkyl, Benzyl, and Hydride Imidophosphorane Complexes

A series of heteroleptic U 4+ benzyl, neopentyl, and methyl complexes supported by the imidophosphorane ligand, [N = P(N,N′-ditert-butylethylenediamide)(diethylamide)] 1− (NP*), were synthesized from the monoiodide precursor, [UI(NP*) 3 ]. These heteroleptic complexes were synthesized through the selective formation of [UI(NP*) 3 ] under transmetalation conditions in the reaction between [UI 4 (1,4-dioxane) 2 ] and K[NP*]. Formation of the homoleptic complex [U(NP*) 4 ] was not observed even in the presence of excess K[NP*]. The oxidation and hydrogenolysis reactivity of the neopentyl complex, [U(Npt)- (NP*) 3 ] (Npt = neopentyl) was explored. While cyclic voltammetry indicates a potentially isolable U5+ alkyl cation, chemical oxidation of the neopentyl complex results in the isolation of a cationic U 4+ complex with a bound diethyl ether in the primary coordination sphere, [U4+(NP*)) 3 (Et 2 O)][(BArF 24 )] (BArF 24 = tetrakis(3,5-bis(trifluoromethyl)phenyl)borate). Notably, hydrogenolysis of [U(Npt)(NP*) 3 ] with H2 gas at −20 °C results in the formation of a terminal hydride intermediate confirmed by in situ NMR spectroscopy and deuterium labeling with D 2 . The connectivity and structural parameters of this hydride intermediate, [UH(NP*) 3 ], which rapidly thermally decomposes to the homoleptic complex, [U(NP*) 4 ], can be confirmed by single-crystal X-ray diffraction studies of a crystal grown by chilling the reaction mixture. The identity of [U(NP*) 4 ] was confirmed by its direct, bulk synthesis from [U(Me)(NP*) 3 ] and HNP* in a protonolysis reaction.

Alkyls↗
DOE OSTI2020

Neptunium extraction by N,N-dialkylamides

Separation of neptunium by solvent extraction has been based on tributylphosphate (TBP) for decades, but TBP is not fully incinerable, which adds to the burden of long-lived radioactive waste. Alternatives to TBP for uranium and plutonium extraction, such as the N , N -diakylamides, previously have been explored in the hopes of transitioning to an extractant that is incinerable. Four N , N -diakylamides, N , N -dihexylhexanamide (DHHA), N , N -dihexyloctanamide (DHOA), N , N -di(2-ethylhexyl)butanamide (DEHBA), and N , N -di(2-ethylhexyl)-iso-butanamide (DEHiBA) were considered in this work for their potential to extract millimolar concentrations of Np(IV), Np(V), and Np(VI) from nitric acid solutions into organic solutions containing 1 M extractant in Exxsol D60. Furthermore, under these conditions the branching of the alkyl substituents affects the extractability of Np(VI) and Np(IV), causing three of the dialkylamides, DHHA, DHOA and DEHBA, to extract neptunium in the expected order Np(VI) > Np(IV) > > Np(V). In contrast, branched DEHiBA is so poor an extractant for Np(IV) that the extraction order becomes Np(VI) > > Np(V) > Np(IV) between 0.1 and 5.6 M HNO 3 due to partial oxidation of the Np(V) in nitric acid.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2020

Materials Data on Np5Ge4 by Materials Project

Np5Ge4 crystallizes in the hexagonal P6_3/mcm space group. The structure is three-dimensional. there are two inequivalent Np sites. In the first Np site, Np is bonded in a 8-coordinate geometry to two equivalent Np and six equivalent Ge atoms. Both Np–Np bond lengths are 2.84 Å. All Np–Ge bond lengths are 3.04 Å. In the second Np site, Np is bonded in a 7-coordinate geometry to seven Ge atoms. There are a spread of Np–Ge bond distances ranging from 2.82–2.90 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a 6-coordinate geometry to six equivalent Np and two equivalent Ge atoms. Both Ge–Ge bond lengths are 2.84 Å. In the second Ge site, Ge is bonded in a 9-coordinate geometry to nine Np atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np5Ge3 by Materials Project

Np5Ge3 crystallizes in the tetragonal I4/mcm space group. The structure is three-dimensional. there are two inequivalent Np sites. In the first Np site, Np is bonded in a 6-coordinate geometry to two equivalent Np and four equivalent Ge atoms. Both Np–Np bond lengths are 2.54 Å. All Np–Ge bond lengths are 2.96 Å. In the second Np site, Np is bonded in a 6-coordinate geometry to six Ge atoms. There are a spread of Np–Ge bond distances ranging from 2.83–3.05 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded in a distorted q6 geometry to eight equivalent Np and two equivalent Ge atoms. Both Ge–Ge bond lengths are 2.54 Å. In the second Ge site, Ge is bonded in a distorted q6 geometry to ten Np atoms.

36 MATERIALS SCIENCE↗