Rb(Cu2As)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-3201238 · Space group: R-3m (#166)

Materials Project API

Basic Information

Formula

Rb(Cu2As)2

MP-ID

mp-3201238

Elements

Sites

Density

6.2461

g/cm³

Volume

130.13

Å³

Cell a

9.2895

Cell b

9.2895

Cell c

9.2895

α Angle

25.43

β Angle

25.43

γ Angle

25.43

Space Group

R-3m

Point Group

-3m

Crystal System

Trigonal

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
9.84	8.9844	100.0	(1,1,1)
25.36	3.5115	2.6	(1,0,0)
25.36	3.5115	1.3	(0,1,0)
28.47	3.1350	25.6	(2,1,1)
29.83	2.9948	22.9	(3,3,3)
30.19	2.9600	5.9	(2,2,1)
30.19	2.9600	11.7	(2,1,2)
34.40	2.6067	38.0	(3,2,2)
36.82	2.4411	4.9	(3,3,2)
36.82	2.4411	9.7	(3,2,3)
40.15	2.2461	1.1	(4,4,4)
42.13	2.1449	34.0	(4,3,3)
44.30	2.0448	29.3	(1,0,-1)
44.30	2.0448	29.3	(0,1,-1)
44.30	2.0448	29.3	(1,-1,0)
45.49	1.9938	9.5	(2,1,0)
45.49	1.9938	4.7	(2,0,1)
51.04	1.7893	32.2	(5,4,4)
53.50	1.7127	1.5	(2,2,0)
53.50	1.7127	2.9	(2,0,2)
54.23	1.6915	1.7	(5,4,5)
54.32	1.6887	8.1	(4,3,2)
54.32	1.6887	12.2	(3,2,4)
54.32	1.6887	4.1	(4,2,3)

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Energy Properties

Formation Energy/atom

-0.20987

eV/atom

Energy/atom

-12.60031

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-12.6003

eV/atom

Volume/atom

18.59

Å³

c/a Ratio

1.0000

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

Cu · 0.571

Element Family

3d-TM

Solute Fraction

0.429

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9557

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.9457

J/mol·K

Ω Parameter

0.0000

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

28.207%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4284

smaller = more stable mixing

VEC

7.286

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.000

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8699

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.647

Family

Cu-based Alloy

Matrix Element

Cu · 0.571

Related Tasks

Related computation task IDs (1)

aaahadoo

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3201238

Reference Citation

The crystal structure and related material properties of Rb(Cu2As)2 were obtained from the Materials Project database (MP-ID: mp-3201238, 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_Rb(Cu2As)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.28948407
_cell_length_b   9.28948416
_cell_length_c   9.28948356
_cell_angle_alpha   25.43229211
_cell_angle_beta   25.43229423
_cell_angle_gamma   25.43228645
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Rb(Cu2As)2
_chemical_formula_sum   'Rb1 Cu4 As2'
_cell_volume   130.13267886
_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
  Rb  Rb0  1  0.00000000  0.00000000  0.00000000  1.0
  Cu  Cu1  1  0.14620711  0.14620711  0.14620711  1.0
  Cu  Cu2  1  0.85379289  0.85379289  0.85379289  1.0
  Cu  Cu3  1  0.44803183  0.44803183  0.44803183  1.0
  Cu  Cu4  1  0.55196817  0.55196817  0.55196817  1.0
  As  As5  1  0.23805904  0.23805904  0.23805904  1.0
  As  As6  1  0.76194096  0.76194096  0.76194096  1.0

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