NpSi
Neptunium silicide is a binary intermetallic compound composed of the actinide neptunium and silicon. It is primarily studied in the context of nuclear materials science and actinide chemistry research.
Overview
Key Properties
Cross-validated computational properties for NpSi, aggregated across 5 databases.
Band GapEnergy needed to move an electron from the valence band to the conduction band. Lower or zero values tend to behave more metallic; larger gaps are more insulating or semiconducting.
Metallic / not reported
Energy Above HullThermodynamic distance from the most stable set of competing phases. 0 eV/atom is on the convex hull; small positive values may still be experimentally accessible.
0.034 eV/atom
Best (lowest) across sources
StabilityA plain-language summary of the best reported energy-above-hull result. It reflects whether the lowest-energy structure is on, near, or far from the stability hull.
Metastable
3 DFT sources
StructuresCount of reported calculated crystal structures for this formula, including alternate polymorphs, source databases, and observed space groups.
38
5 databases, 10 space groups
Validation
Cross-Source DFT Agreement
How well independent DFT databases agree on the thermodynamics of NpSi. Tight agreement means computed properties can be trusted without re-running calculations.
Agreement ScoreA normalized confidence score summarizing how closely independent DFT databases agree. Higher scores mean tighter cross-source agreement.
1.00 / 1.00
Trust tier: high
Hull SpreadDifference between the highest and lowest energy-above-hull values reported by comparable sources. Smaller spread means less thermodynamic disagreement.
0.000 eV
EAH spread across sources
Sources ComparedNumber and names of computational sources with comparable entries for this formula.
3
jarvis, materials_project, nomad
Space Group ConsensusWhether independent sources predict the same crystal symmetry for the lowest-energy structure.
All match
Crystallography
Reported Structures
Lowest-energy structures reported for NpSi, ranked by energy above hull.
| Space GroupSymmetry classification of the crystal arrangement. The number is the international space-group index. | Crystal SystemBroad lattice family, such as cubic, tetragonal, monoclinic, or triclinic, derived from unit-cell symmetry. | Band Gap (eV)Electronic gap calculated for this specific reported structure, measured in electronvolts. | E above hull (eV/atom)Thermodynamic distance from the convex hull for this structure, normalized per atom. Lower is generally more stable. | E/atom (eV)Computed total energy normalized per atom. Use energy above hull, not this value alone, when comparing stability. | Density (g/cm³)Mass per relaxed crystal volume, reported in grams per cubic centimeter. |
|---|---|---|---|---|---|
| Cmcm (No. 63) | orthorhombic | 0.00 | 0.0344 | -46.291 | 10.66 |
| Pnma (No. 62) | orthorhombic | 0.00 | 0.2807 | -46.045 | 13.12 |
| P21 (No. 4) | Monoclinic | — | — | — | 8.97 |
| No. 0 | unknown | — | — | — | 2.60 |
| Cm (No. 8) | Monoclinic | — | — | — | 8.50 |
| Cmcm (No. 63) | Orthorhombic | — | — | — | 9.74 |
| Cmcm (No. 63) | Orthorhombic | — | — | — | 9.98 |
| Cm (No. 8) | Monoclinic | — | — | — | 8.91 |
| Cm (No. 8) | Monoclinic | — | — | — | 10.78 |
| Cm (No. 8) | Monoclinic | — | — | — | 10.93 |
| P1 (No. 1) | Triclinic | — | — | — | 6.54 |
| P1 (No. 1) | Triclinic | — | — | — | 7.12 |
Uses
Applications
Where NpSi is used.
Nuclear fuel researchActinide fundamental property studies
Reference
Frequently Asked Questions
Common questions about NpSi, answered from cross-validated data.
What is NpSi?
Neptunium silicide is a binary intermetallic compound composed of the actinide neptunium and silicon. It is primarily studied in the context of nuclear materials science and actinide chemistry research.
More questions
What is NpSi used for?
NpSi is used in nuclear fuel research and actinide fundamental property studies.
What is the band gap of NpSi?
NpSi is computed to be metallic (no band gap) in the reported DFT structures.
Is NpSi a metal, semiconductor, or insulator?
Computed band structures report no gap, so it is metallic.
Is NpSi thermodynamically stable?
NpSi has a lowest energy above hull of 0.034 eV/atom (metastable).
What is the crystal structure of NpSi?
The lowest-energy reported polymorph of NpSi is orthorhombic symmetry, space group Cmcm (No. 63).
What is the density of NpSi?
The computed density of the ground-state structure of NpSi is 10.66 g/cm³.
How many polymorphs of NpSi are known?
38 structures of NpSi are reported across 5 databases, spanning 10 distinct space groups.
What elements does NpSi contain?
NpSi contains Np and Si (2 elements).
Where does the data for NpSi come from?
NpSi data is cross-referenced from materials_project, mpaloe, cod.
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Related Compounds
Other Silicon Anode Materials in the database.
Data sources & attribution
- materials_project — Data from the Materials Project. Cite: Jain et al., APL Materials 1, 011002 (2013).
- mpaloe — Data from mpaloe.
- cod — Data from the Crystallography Open Database. Cite: Grazulis et al., Nucleic Acids Res. 40, D420 (2012).
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