Ca8Fe2CuN8

High-Entropy Materials HEA

MP-ID: mp-3292495 · Space group: C2/m (#12)

Materials Project API

Basic Information

Formula

Ca8Fe2CuN8

MP-ID

mp-3292495

Elements

Sites

Density

3.3629

g/cm³

Volume

300.18

Å³

Cell a

9.2215

Cell b

4.9804

Cell c

7.0554

α Angle

90.00

β Angle

74.78

γ Angle

74.33

Space Group

C2/m

Point Group

2/m

Crystal System

Monoclinic

Bravais Lattice

Stability

Yes

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
10.36	8.5426	3.1	(1,0,0)
14.28	6.2015	4.8	(1,0,1)
18.56	4.7814	2.0	(0,1,0)
18.78	4.7241	16.6	(1,0,-1)
20.80	4.2713	4.7	(2,0,0)
21.34	4.1628	3.0	(2,0,1)
21.91	4.0575	36.9	(0,1,-1)
23.73	3.7490	12.2	(1,-1,0)
23.73	3.7490	12.2	(2,1,0)
27.54	3.2389	5.7	(2,0,-1)
28.79	3.1008	9.5	(2,0,2)
29.21	3.0577	2.9	(1,-1,-1)
30.55	2.9258	10.2	(3,0,1)
30.89	2.8950	10.8	(1,0,-2)
31.13	2.8731	32.1	(0,1,-2)
31.42	2.8475	18.1	(3,0,0)
31.52	2.8381	17.5	(2,-1,1)
31.52	2.8381	17.5	(3,1,1)
31.76	2.8176	21.1	(2,-1,0)
32.24	2.7762	3.6	(1,-1,2)
32.24	2.7762	3.6	(2,1,2)
33.52	2.6731	57.3	(1,1,-2)
35.19	2.5506	2.6	(3,0,2)
36.07	2.4902	100.0	(1,2,0)

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Energy Properties

Formation Energy/atom

-0.91238

eV/atom

Energy/atom

-9.80764

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-9.8076

eV/atom

Volume/atom

15.80

Å³

c/a Ratio

0.7651

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

5.0000

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.016660

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Ca · 0.421

Element Family

Alkali-AlkEarth

Solute Fraction

0.579

Interstitial Fraction

0.421

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1204

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.3147

J/mol·K

Ω Parameter

0.0789

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

41.689%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.9381

smaller = more stable mixing

VEC

4.368

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-89.491

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8082

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfiol

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3292495

Reference Citation

The crystal structure and related material properties of Ca8Fe2CuN8 were obtained from the Materials Project database (MP-ID: mp-3292495, 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_Ca8Fe2CuN8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.22153328
_cell_length_b   4.98041304
_cell_length_c   7.05542019
_cell_angle_alpha   90.00001037
_cell_angle_beta   74.78063125
_cell_angle_gamma   74.33321398
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca8Fe2CuN8
_chemical_formula_sum   'Ca8 Fe2 Cu1 N8'
_cell_volume   300.17617629
_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
  Ca  Ca0  1  0.06049996  0.96975002  0.74357101  1.0
  Ca  Ca1  1  0.93950004  0.03024998  0.25642899  1.0
  Ca  Ca2  1  0.67012653  0.66493773  0.46961894  1.0
  Ca  Ca3  1  0.32987347  0.33506227  0.53038106  1.0
  Ca  Ca4  1  0.81849227  0.59075436  0.97160343  1.0
  Ca  Ca5  1  0.18150773  0.40924564  0.02839657  1.0
  Ca  Ca6  1  0.59963562  0.20018269  0.81057630  1.0
  Ca  Ca7  1  0.40036438  0.79981731  0.18942370  1.0
  Fe  Fe8  1  0.37729856  0.81134972  0.79050973  1.0
  Fe  Fe9  1  0.62270144  0.18865028  0.20949027  1.0
  Cu  Cu10  1  0.00000000  0.50000000  0.50000000  1.0
  N  N11  1  0.21097134  0.89451433  0.99329145  1.0
  N  N12  1  0.78902866  0.10548567  0.00670855  1.0
  N  N13  1  0.35155292  0.82422304  0.55588272  1.0
  N  N14  1  0.64844708  0.17577696  0.44411728  1.0
  N  N15  1  0.56293393  0.71853304  0.82920018  1.0
  N  N16  1  0.43706607  0.28146696  0.17079982  1.0
  N  N17  1  0.06091309  0.46954395  0.73231370  1.0
  N  N18  1  0.93908691  0.53045605  0.26768630  1.0

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