Np4Al18PdRh5
High-Entropy Materials HEAMP-ID: mp-3296910 · Space group: C2 (#5)
Basic Information
Formula
Np4Al18PdRh5
MP-ID
mp-3296910
Elements
4
Sites
28
Density
7.2328
g/cm³
Volume
471.71
ų
Cell a
7.5696
Å
Cell b
7.5696
Å
Cell c
9.4637
Å
α Angle
90.01
°
β Angle
90.01
°
γ Angle
119.55
°
Space Group
C2
Point Group
2
Crystal System
Monoclinic
Bravais Lattice
mC
Stability
Yes
Packing Fraction
-
X-ray Diffraction
Diffraction Pattern
X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å
Diffraction Peaks (Top 24)
| 2θ | d (Å) | I | hkl |
|---|---|---|---|
| 13.45 | 6.5848 | 15.8 | (0,1,-1,0) |
| 13.45 | 6.5848 | 15.8 | (1,0,-1,0) |
| 13.54 | 6.5407 | 49.4 | (1,-1,0,0) |
| 16.40 | 5.4060 | 28.9 | (0,1,-1,-1) |
| 16.40 | 5.4060 | 28.9 | (1,0,-1,-1) |
| 16.40 | 5.4042 | 55.0 | (1,0,-1,1) |
| 18.75 | 4.7318 | 8.1 | (0,0,0,2) |
| 23.14 | 3.8433 | 4.1 | (0,1,-1,-2) |
| 23.14 | 3.8433 | 4.1 | (1,0,-1,-2) |
| 23.15 | 3.8419 | 9.9 | (1,0,-1,2) |
| 23.20 | 3.8338 | 27.4 | (1,-1,0,2) |
| 23.51 | 3.7847 | 2.7 | (2,-1,-1,0) |
| 25.19 | 3.5351 | 45.3 | (1,1,-2,-1) |
| 25.20 | 3.5341 | 47.8 | (1,1,-2,1) |
| 25.34 | 3.5144 | 100.0 | (2,-1,-1,-1) |
| 25.35 | 3.5138 | 94.6 | (2,-1,-1,1) |
| 27.08 | 3.2924 | 7.7 | (2,0,-2,0) |
| 27.27 | 3.2703 | 23.1 | (2,-2,0,0) |
| 28.71 | 3.1099 | 20.3 | (2,0,-2,-1) |
| 28.71 | 3.1092 | 21.3 | (2,0,-2,1) |
| 30.11 | 2.9684 | 57.2 | (1,1,-2,-2) |
| 30.12 | 2.9671 | 50.7 | (1,1,-2,2) |
| 30.24 | 2.9559 | 96.6 | (2,-1,-1,-2) |
| 30.24 | 2.9553 | 54.0 | (1,-2,1,-2) |
Energy Properties
Formation Energy/atom
-0.79458
eV/atom
Energy/atom
-22.11302
eV/atom
Energy above Hull
0.0000
eV/atom
Uncorrected Energy
-22.1130
eV/atom
Volume/atom
16.85
ų
c/a Ratio
1.2502
Electronic Properties
Metallic
Metal
Band Gap
0
eV
Direct Gap
No
CBM
N/A
eV
Magnetic Properties
Magnetic
Yes
Total Mag. Moment
15.8986
μB
Mag. Ordering
FM
Mag. Sites
4
Magnetization/Volume
0.033700
μB/ų
Elastic Properties
Elastic data not available
Feature Analysis
Composition Overview
Element Composition (atomic fraction)
Composition Info
Major / Matrix Element
Al · 0.643
Element Family
PostTransition-Noble
Solute Fraction
0.357
Interstitial Fraction
0.000
High-Entropy Alloy Features
Composite Radar (normalized)
Element-Class Share
Mix Entropy ΔS/R
0.9887
HEA criterion (>1.0 = high entropy)
Mix Entropy ΔS
8.2198
J/mol·K
Ω Parameter
0.9244
Ω > 1.1 favors solid solution
Atomic Size Mismatch δr
8.527%
δr < 6.6% favors single-phase solid solution
Electronegativity Diff Δχ
0.3008
smaller = more stable mixing
VEC
4.542
valence electron concentration, affects phase stability
Mix Enthalpy ΔH_mix
-10.625
kJ/mol; negative = exothermic mixing
Entropy Norm
0.7132
SS Former
0
Phase Tendency
IM
Related Tasks
Related computation task IDs (1)
Citation & References
Materials Project Page
https://materialsproject.org/materials/mp-3296910
Reference Citation
The crystal structure and related material properties of Np4Al18PdRh5 were obtained from the Materials Project database (MP-ID: mp-3296910, database version v2026.04.13).
Literature Citation
Horton, M.K., Huck, P., Yang, R.X. et al. Accelerated data-driven materials science with the Materials Project. Nat. Mater. 24, 1522–1532 (2025). https://doi.org/10.1038/s41563-025-02272-0
3D Crystal Structure Rendering
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Raw CIF Data
# generated using pymatgen
data_Np4Al18PdRh5
_symmetry_space_group_name_H-M 'P 1'
_cell_length_a 7.56961357
_cell_length_b 7.56961429
_cell_length_c 9.46365056
_cell_angle_alpha 90.01226070
_cell_angle_beta 90.01225727
_cell_angle_gamma 119.55353423
_symmetry_Int_Tables_number 1
_chemical_formula_structural Np4Al18PdRh5
_chemical_formula_sum 'Np4 Al18 Pd1 Rh5'
_cell_volume 471.70780412
_cell_formula_units_Z 1
loop_
_symmetry_equiv_pos_site_id
_symmetry_equiv_pos_as_xyz
1 'x, y, z'
loop_
_atom_site_type_symbol
_atom_site_label
_atom_site_symmetry_multiplicity
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
Np Np0 1 0.99246677 0.66795826 0.75241668 1.0
Np Np1 1 0.00329790 0.33007487 0.24747329 1.0
Np Np2 1 0.66992513 0.99670210 0.75252671 1.0
Np Np3 1 0.33204174 0.00753323 0.24758332 1.0
Al Al4 1 0.12949078 0.12845831 0.74937631 1.0
Al Al5 1 0.87154169 0.87050922 0.25062369 1.0
Al Al6 1 0.00425065 0.33511131 0.57390521 1.0
Al Al7 1 0.00338824 0.66862500 0.42635589 1.0
Al Al8 1 0.99855726 0.66543138 0.07438732 1.0
Al Al9 1 0.33456862 0.00144274 0.92561268 1.0
Al Al10 1 0.00280050 0.33483197 0.92471449 1.0
Al Al11 1 0.66516803 0.99719950 0.07528551 1.0
Al Al12 1 0.66488869 0.99574935 0.42609479 1.0
Al Al13 1 0.33137500 0.99661176 0.57364411 1.0
Al Al14 1 0.33429579 0.33444008 0.04586964 1.0
Al Al15 1 0.66555992 0.66570421 0.95413036 1.0
Al Al16 1 0.66670869 0.66993985 0.55023942 1.0
Al Al17 1 0.33006015 0.33329131 0.44976058 1.0
Al Al18 1 0.34103033 0.54861098 0.74973018 1.0
Al Al19 1 0.66007583 0.45434176 0.24749325 1.0
Al Al20 1 0.54565824 0.33992417 0.75250675 1.0
Al Al21 1 0.45138902 0.65896967 0.25026982 1.0
Pd Pd22 1 0.67075044 0.32924956 0.50000000 1.0
Rh Rh23 1 0.32966252 0.67033748 0.50000000 1.0
Rh Rh24 1 0.32849754 0.67150246 0.00000000 1.0
Rh Rh25 1 0.67188503 0.32811497 0.00000000 1.0
Rh Rh26 1 0.00025915 0.99974085 0.50000000 1.0
Rh Rh27 1 0.00040235 0.99959765 1.00000000 1.0
