HfNp3Bi4Sb

High-Entropy Materials HEA

MP-ID: mp-3292496 · Space group: Ama2 (#40)

Materials Project API

Basic Information

Formula

HfNp3Bi4Sb

MP-ID

mp-3292496

Elements

Sites

Density

11.9422

g/cm³

Volume

513.69

Å³

Cell a

9.5821

Cell b

9.5954

Cell c

6.4545

α Angle

90.00

β Angle

90.00

γ Angle

120.05

Space Group

Ama2

Point Group

mm2

Crystal System

Orthorhombic

Bravais Lattice

Stability

Packing Fraction

X-ray Diffraction

Diffraction Pattern

Target / Radiation

X-axis: 2θ (°); Y-axis: relative intensity; Cu Kα ; λ=1.5418 Å

Diffraction Peaks (Top 24)

2θ	d (Å)	I	hkl
10.67	8.2943	3.0	(1,0,0)
21.43	4.1472	2.1	(2,0,0)
23.10	3.8505	7.0	(1,-2,1)
23.12	3.8470	4.2	(2,-1,1)
23.12	3.8470	4.2	(1,1,1)
25.50	3.4925	1.8	(2,-2,1)
25.50	3.4925	1.8	(0,2,1)
27.64	3.2272	25.7	(0,0,2)
28.42	3.1406	1.6	(2,-3,0)
28.42	3.1406	1.6	(1,-3,0)
28.45	3.1375	3.1	(3,-2,0)
28.45	3.1374	3.1	(1,2,0)
28.47	3.1356	1.8	(3,-1,0)
28.47	3.1356	1.8	(2,1,0)
29.70	3.0076	1.7	(1,0,2)
31.68	2.8241	30.6	(2,-3,1)
31.68	2.8240	30.6	(1,-3,1)
31.71	2.8218	27.1	(3,-2,1)
31.71	2.8217	27.1	(1,2,1)
31.73	2.8204	32.5	(3,-1,1)
31.73	2.8204	32.4	(2,1,1)
32.33	2.7687	79.6	(3,-3,0)
32.34	2.7686	79.6	(0,3,0)
32.38	2.7648	80.0	(3,0,0)

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Energy Properties

Formation Energy/atom

-0.58765

eV/atom

Energy/atom

-62.13648

eV/atom

Energy above Hull

0.0069

eV/atom

Uncorrected Energy

-62.1365

eV/atom

Volume/atom

28.54

Å³

c/a Ratio

0.6736

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

23.8763

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.046480

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Bi · 0.444

Element Family

PostTransition-Noble

Solute Fraction

0.556

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.2149

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

10.1006

J/mol·K

Ω Parameter

3.6555

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

5.803%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3390

smaller = more stable mixing

VEC

4.833

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-2.554

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8764

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfiom

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3292496

Reference Citation

The crystal structure and related material properties of HfNp3Bi4Sb were obtained from the Materials Project database (MP-ID: mp-3292496, 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_HfNp3Bi4Sb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.58204587
_cell_length_b   9.59538448
_cell_length_c   6.45444615
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   120.04724789
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HfNp3Bi4Sb
_chemical_formula_sum   'Hf2 Np6 Bi8 Sb2'
_cell_volume   513.69255958
_cell_formula_units_Z   2
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
  Hf  Hf0  1  0.00589867  0.00295298  0.49999598  1.0
  Hf  Hf1  1  0.00589867  0.00295298  0.00000402  1.0
  Np  Np2  1  0.37983905  0.00552328  0.75000000  1.0
  Np  Np3  1  0.37985001  0.37435048  0.25000000  1.0
  Np  Np4  1  0.00493013  0.62216648  0.25000000  1.0
  Np  Np5  1  0.00485392  0.38271263  0.75000000  1.0
  Np  Np6  1  0.61322818  0.61431502  0.75000000  1.0
  Np  Np7  1  0.61320908  0.99886008  0.25000000  1.0
  Bi  Bi8  1  0.33369176  0.66684181  0.50001829  1.0
  Bi  Bi9  1  0.66800892  0.33400491  0.00000905  1.0
  Bi  Bi10  1  0.66800892  0.33400491  0.49999095  1.0
  Bi  Bi11  1  0.33369176  0.66684181  0.99998171  1.0
  Bi  Bi12  1  0.73629880  0.99966602  0.75000000  1.0
  Bi  Bi13  1  0.73632758  0.73659341  0.25000000  1.0
  Bi  Bi14  1  0.99803279  0.26286116  0.25000000  1.0
  Bi  Bi15  1  0.99804141  0.73519497  0.75000000  1.0
  Sb  Sb16  1  0.26009184  0.99846840  0.25000000  1.0
  Sb  Sb17  1  0.26010051  0.26168968  0.75000000  1.0

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