Ce2Al9Ir2Os

High-Entropy Materials HEA

MP-ID: mp-3296269 · Space group: Cmcm (#63)

Materials Project API

Basic Information

Formula

Ce2Al9Ir2Os

MP-ID

mp-3296269

Elements

Sites

Density

7.7211

g/cm³

Volume

472.17

Å³

Cell a

7.5651

Cell b

7.5651

Cell c

9.4277

α Angle

90.00

β Angle

90.00

γ Angle

118.94

Space Group

Cmcm

Point Group

mmm

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
13.37	6.6204	3.5	(1,0,-1,0)
13.59	6.5163	3.7	(1,-1,0,0)
16.36	5.4179	4.1	(0,1,-1,1)
16.36	5.4179	4.1	(1,0,-1,1)
18.83	4.7138	20.6	(0,0,0,2)
23.14	3.8429	19.3	(1,1,-2,0)
23.16	3.8399	1.6	(1,0,-1,2)
23.52	3.7819	34.9	(2,-1,-1,0)
25.02	3.5586	8.7	(1,1,-2,1)
25.38	3.5100	7.7	(1,-2,1,1)
25.38	3.5100	7.7	(2,-1,-1,1)
27.37	3.2582	2.4	(2,-2,0,0)
28.58	3.1233	3.7	(2,0,-2,1)
30.00	2.9785	48.0	(1,1,-2,2)
30.30	2.9499	100.0	(2,-1,-1,2)
31.51	2.8390	2.9	(1,0,-1,3)
33.07	2.7090	1.7	(2,0,-2,2)
33.43	2.6802	7.4	(2,-2,0,2)
35.72	2.5138	3.1	(2,1,-3,0)
36.95	2.4327	11.2	(1,1,-2,3)
37.20	2.4170	21.7	(2,-1,-1,3)
37.42	2.4031	7.0	(3,-1,-2,1)
38.18	2.3569	30.2	(0,0,0,4)
39.54	2.2791	2.2	(2,0,-2,3)

Get direct link

Energy Properties

Formation Energy/atom

-0.82843

eV/atom

Energy/atom

-20.82658

eV/atom

Energy above Hull

0.0003

eV/atom

Uncorrected Energy

-20.8266

eV/atom

Volume/atom

16.86

Å³

c/a Ratio

1.2462

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

1.4616

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.003100

μB/Å³

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

1.0285

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.5511

J/mol·K

Ω Parameter

0.4656

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

10.594%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3251

smaller = more stable mixing

VEC

4.214

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-25.348

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7419

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfodp

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3296269

Reference Citation

The crystal structure and related material properties of Ce2Al9Ir2Os were obtained from the Materials Project database (MP-ID: mp-3296269, 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

Loading 3D structure…

Style: Ball & Stick | Drag to rotate · Scroll to zoom · Right-click to pan

Raw CIF Data

# generated using pymatgen
data_Ce2Al9Ir2Os
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.56506296
_cell_length_b   7.56506341
_cell_length_c   9.42764875
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   118.94070730
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ce2Al9Ir2Os
_chemical_formula_sum   'Ce4 Al18 Ir4 Os2'
_cell_volume   472.16804457
_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
  Ce  Ce0  1  0.99509573  0.67930796  0.25000000  1.0
  Ce  Ce1  1  0.00490427  0.32069204  0.75000000  1.0
  Ce  Ce2  1  0.67930796  0.99509573  0.25000000  1.0
  Ce  Ce3  1  0.32069204  0.00490427  0.75000000  1.0
  Al  Al4  1  0.00409587  0.33802691  0.07514263  1.0
  Al  Al5  1  0.99590413  0.66197309  0.92485737  1.0
  Al  Al6  1  0.99590413  0.66197309  0.57514263  1.0
  Al  Al7  1  0.33802691  0.00409587  0.42485737  1.0
  Al  Al8  1  0.00409587  0.33802691  0.42485737  1.0
  Al  Al9  1  0.66197309  0.99590413  0.57514263  1.0
  Al  Al10  1  0.66197309  0.99590413  0.92485737  1.0
  Al  Al11  1  0.33802691  0.00409587  0.07514263  1.0
  Al  Al12  1  0.33347120  0.33347120  0.54221940  1.0
  Al  Al13  1  0.66652880  0.66652880  0.45778060  1.0
  Al  Al14  1  0.66652880  0.66652880  0.04221940  1.0
  Al  Al15  1  0.33347120  0.33347120  0.95778060  1.0
  Al  Al16  1  0.13552877  0.13552877  0.25000000  1.0
  Al  Al17  1  0.86447123  0.86447123  0.75000000  1.0
  Al  Al18  1  0.34325239  0.55107564  0.25000000  1.0
  Al  Al19  1  0.65674761  0.44892436  0.75000000  1.0
  Al  Al20  1  0.55107564  0.34325239  0.25000000  1.0
  Al  Al21  1  0.44892436  0.65674761  0.75000000  1.0
  Ir  Ir22  1  0.67207841  0.32792159  0.00000000  1.0
  Ir  Ir23  1  0.32792159  0.67207841  0.00000000  1.0
  Ir  Ir24  1  0.32792159  0.67207841  0.50000000  1.0
  Ir  Ir25  1  0.67207841  0.32792159  0.50000000  1.0
  Os  Os26  1  0.00000000  0.00000000  0.00000000  1.0
  Os  Os27  1  0.00000000  0.00000000  0.50000000  1.0

Get direct link