CaAc(BIr)4

High-Entropy Materials HEA

MP-ID: mp-3249711 · Space group: F222 (#22)

Materials Project API

Basic Information

Formula

CaAc(BIr)4

MP-ID

mp-3249711

Elements

Sites

Density

11.6407

g/cm³

Volume

153.95

Å³

Cell a

7.1586

Cell b

6.1824

Cell c

5.6035

α Angle

74.62

β Angle

56.38

γ Angle

49.00

Space Group

F222

Point Group

222

Crystal System

Orthorhombic

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
16.45	5.3883	7.0	(1,1,0)
18.83	4.7129	6.7	(1,0,1)
19.26	4.6089	43.6	(1,1,1)
25.10	3.5474	7.7	(0,1,-1)
29.47	3.0311	2.3	(0,1,1)
30.44	2.9366	100.0	(2,1,0)
33.17	2.7005	9.0	(2,1,2)
33.25	2.6942	11.0	(2,2,0)
33.93	2.6418	6.0	(1,2,1)
35.20	2.5494	92.7	(1,1,2)
38.19	2.3565	37.9	(2,0,2)
38.49	2.3390	2.5	(1,2,-1)
39.09	2.3044	3.6	(2,2,2)
40.96	2.2032	50.0	(0,2,-1)
41.84	2.1590	1.4	(1,-1,2)
45.70	1.9852	21.7	(3,2,0)
46.74	1.9434	4.5	(1,2,2)
49.21	1.8517	9.2	(3,3,2)
49.21	1.8517	9.2	(1,1,-2)
51.47	1.7755	3.6	(3,0,2)
51.52	1.7737	7.8	(0,2,-2)
52.00	1.7585	1.9	(3,2,3)
52.89	1.7312	11.0	(2,3,2)
52.89	1.7312	11.0	(2,0,-1)

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Energy Properties

Formation Energy/atom

-0.78803

eV/atom

Energy/atom

-32.23789

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-32.2379

eV/atom

Volume/atom

15.39

Å³

c/a Ratio

0.7828

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0000

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000000

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

B · 0.400

Element Family

Metalloid-Nonmetal

Solute Fraction

0.600

Interstitial Fraction

0.400

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1936

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.9232

J/mol·K

Ω Parameter

1.2397

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

30.138%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4345

smaller = more stable mixing

VEC

5.200

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-18.242

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8610

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahcxgx

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3249711

Reference Citation

The crystal structure and related material properties of CaAc(BIr)4 were obtained from the Materials Project database (MP-ID: mp-3249711, 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_CaAc(BIr)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.15858484
_cell_length_b   6.18234765
_cell_length_c   5.60347426
_cell_angle_alpha   74.62068939
_cell_angle_beta   56.37725909
_cell_angle_gamma   49.00204346
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaAc(BIr)4
_chemical_formula_sum   'Ca1 Ac1 B4 Ir4'
_cell_volume   153.94643619
_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  0.25000000  0.25000000  0.25000000  1.0
  Ac  Ac1  1  0.00000000  0.00000000  0.00000000  1.0
  B  B2  1  0.32733900  0.67266100  0.32733900  1.0
  B  B3  1  0.57110834  0.92889166  0.57110834  1.0
  B  B4  1  0.67266100  0.32733900  0.67266100  1.0
  B  B5  1  0.92889166  0.57110834  0.92889166  1.0
  Ir  Ir6  1  0.63280083  0.63280083  0.36719917  1.0
  Ir  Ir7  1  0.87855337  0.87855337  0.62144663  1.0
  Ir  Ir8  1  0.62144663  0.62144663  0.87855337  1.0
  Ir  Ir9  1  0.36719917  0.36719917  0.63280083  1.0

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