Na4Cr2As(CO4)4

High-Entropy Materials HEA

MP-ID: mp-770736 · Space group: Fddd (#70)

Materials Project API

Basic Information

Formula

Na4Cr2As(CO4)4

MP-ID

mp-770736

Elements

Sites

Density

2.7590

g/cm³

Volume

692.04

Å³

Cell a

9.9621

Cell b

9.8230

Cell c

9.9621

α Angle

60.76

β Angle

92.10

γ Angle

60.76

Space Group

Fddd

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
10.92	8.1046	27.0	(1,0,0)
10.92	8.1046	9.0	(0,1,1)
17.73	5.0014	51.4	(1,1,-1)
17.73	5.0014	51.4	(1,-1,-1)
17.82	4.9777	100.0	(2,1,0)
18.06	4.9113	1.9	(1,0,1)
20.66	4.2992	76.4	(1,0,-2)
20.66	4.2992	76.4	(2,0,-1)
21.08	4.2145	41.7	(0,1,-1)
21.08	4.2145	41.7	(1,-1,0)
21.22	4.1862	88.3	(2,1,1)
21.93	4.0523	36.1	(2,0,0)
25.53	3.4889	4.1	(0,2,0)
25.77	3.4569	5.4	(2,2,2)
27.52	3.2414	21.7	(2,-1,-1)
27.63	3.2284	21.9	(3,1,0)
27.95	3.1921	7.7	(2,0,1)
30.87	2.8963	1.2	(3,2,-1)
31.31	2.8570	5.7	(2,-1,0)
31.46	2.8437	4.5	(3,1,1)
32.51	2.7539	74.8	(3,0,-2)
33.16	2.7015	12.7	(3,0,0)
33.34	2.6875	80.8	(1,-2,0)
33.62	2.6655	82.5	(3,2,2)

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Energy Properties

Formation Energy/atom

-1.91768

eV/atom

Energy/atom

-7.30414

eV/atom

Energy above Hull

0.0849

eV/atom

Uncorrected Energy

-6.7490

eV/atom

Volume/atom

12.82

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

11.9997

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.017340

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.593

Element Family

Metalloid-Nonmetal

Solute Fraction

0.407

Interstitial Fraction

0.148

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1907

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.8997

J/mol·K

Ω Parameter

0.8563

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

51.310%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.9374

smaller = more stable mixing

VEC

3.667

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-9.892

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7398

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaabzgvr aaaedhas

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-770736

Reference Citation

The crystal structure and related material properties of Na4Cr2As(CO4)4 were obtained from the Materials Project database (MP-ID: mp-770736, 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_Na4Cr2As(CO4)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.96208527
_cell_length_b   9.82297641
_cell_length_c   9.96208552
_cell_angle_alpha   60.75998702
_cell_angle_beta   92.10341891
_cell_angle_gamma   60.75998078
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Na4Cr2As(CO4)4
_chemical_formula_sum   'Na8 Cr4 As2 C8 O32'
_cell_volume   692.03850648
_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
  Na  Na0  1  0.08855100  0.82289700  0.83855100  1.0
  Na  Na1  1  0.08844600  0.25000000  0.83844600  1.0
  Na  Na2  1  0.33844600  0.75000000  0.58844600  1.0
  Na  Na3  1  0.33855100  0.32289700  0.58855100  1.0
  Na  Na4  1  0.66144900  0.67710300  0.41144900  1.0
  Na  Na5  1  0.66155400  0.25000000  0.41155400  1.0
  Na  Na6  1  0.91155400  0.75000000  0.16155400  1.0
  Na  Na7  1  0.91144900  0.17710300  0.16144900  1.0
  Cr  Cr8  1  0.00000000  0.50000000  0.00000000  1.0
  Cr  Cr9  1  0.50000000  0.00000000  0.50000000  1.0
  Cr  Cr10  1  0.50000000  0.50000000  0.00000000  1.0
  Cr  Cr11  1  0.50000000  0.00000000  0.00000000  1.0
  As  As12  1  0.12500000  0.75000000  0.37500000  1.0
  As  As13  1  0.87500000  0.25000000  0.62500000  1.0
  C  C14  1  0.36504200  0.92420500  0.78298900  1.0
  C  C15  1  0.28298900  0.42420500  0.86504200  1.0
  C  C16  1  0.71075300  0.92420500  0.79280600  1.0
  C  C17  1  0.70719400  0.57579500  0.78924700  1.0
  C  C18  1  0.29280600  0.42420500  0.21075300  1.0
  C  C19  1  0.28924700  0.07579500  0.20719400  1.0
  C  C20  1  0.71701100  0.57579500  0.13495800  1.0
  C  C21  1  0.63495800  0.07579500  0.21701100  1.0
  O  O22  1  0.35907800  0.78629200  0.89315700  1.0
  O  O23  1  0.06007800  0.89791200  0.43957200  1.0
  O  O24  1  0.36752900  0.95000400  0.64322300  1.0
  O  O25  1  0.14322300  0.45000400  0.86752900  1.0
  O  O26  1  0.68246600  0.95000400  0.90677300  1.0
  O  O27  1  0.30965600  0.54428300  0.85917100  1.0
  O  O28  1  0.04201000  0.89791200  0.16251600  1.0
  O  O29  1  0.06042800  0.60208800  0.43992200  1.0
  O  O30  1  0.40345400  0.95571700  0.35393900  1.0
  O  O31  1  0.59322700  0.54999600  0.81753400  1.0
  O  O32  1  0.39315700  0.28629200  0.85907800  1.0
  O  O33  1  0.33748400  0.60208800  0.45799000  1.0
  O  O34  1  0.85463000  0.78629200  0.82055000  1.0
  O  O35  1  0.67945000  0.71370800  0.64537000  1.0
  O  O36  1  0.35917100  0.04428300  0.80965600  1.0
  O  O37  1  0.14606100  0.54428300  0.09654600  1.0
  O  O38  1  0.85393900  0.45571700  0.90345400  1.0
  O  O39  1  0.64082900  0.95571700  0.19034400  1.0
  O  O40  1  0.32055000  0.28629200  0.35463000  1.0
  O  O41  1  0.14537000  0.21370800  0.17945000  1.0
  O  O42  1  0.66251600  0.39791200  0.54201000  1.0
  O  O43  1  0.60684300  0.71370800  0.14092200  1.0
  O  O44  1  0.40677300  0.45000400  0.18246600  1.0
  O  O45  1  0.59654600  0.04428300  0.64606100  1.0
  O  O46  1  0.93957200  0.39791200  0.56007800  1.0
  O  O47  1  0.95799000  0.10208800  0.83748400  1.0
  O  O48  1  0.69034400  0.45571700  0.14082900  1.0
  O  O49  1  0.31753400  0.04999600  0.09322700  1.0
  O  O50  1  0.85677700  0.54999600  0.13247100  1.0
  O  O51  1  0.63247100  0.04999600  0.35677700  1.0
  O  O52  1  0.93992200  0.10208800  0.56042800  1.0
  O  O53  1  0.64092200  0.21370800  0.10684300  1.0

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