ErPa(Al3Rh)3

High-Entropy Materials HEA

MP-ID: mp-3295305 · Space group: P2_1/m (#11)

Materials Project API

Basic Information

Formula

ErPa(Al3Rh)3

MP-ID

mp-3295305

Elements

Sites

Density

6.8683

g/cm³

Volume

459.29

Å³

Cell a

7.5348

Cell b

7.5437

Cell c

9.2898

α Angle

90.00

β Angle

90.00

γ Angle

119.56

Space Group

P2_1/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
13.49	6.5615	3.4	(0,1,-1,0)
13.51	6.5539	31.5	(1,0,-1,0)
13.59	6.5148	39.4	(1,-1,0,0)
16.54	5.3595	62.3	(0,1,-1,1)
16.55	5.3553	27.0	(1,0,-1,1)
16.62	5.3339	5.6	(1,-1,0,1)
19.11	4.6449	1.3	(0,0,0,2)
23.44	3.7945	3.7	(1,1,-2,0)
23.47	3.7911	1.4	(0,1,-1,2)
23.48	3.7896	15.8	(1,0,-1,2)
23.52	3.7820	18.1	(1,-1,0,2)
23.59	3.7717	3.8	(1,-2,1,0)
23.62	3.7673	3.6	(2,-1,-1,0)
25.36	3.5127	73.4	(1,1,-2,1)
25.49	3.4947	74.7	(1,-2,1,1)
25.51	3.4912	74.4	(2,-1,-1,1)
27.21	3.2769	6.1	(2,0,-2,0)
27.38	3.2574	18.1	(2,-2,0,0)
28.86	3.0935	22.1	(0,2,-2,1)
28.89	3.0903	13.0	(2,0,-2,1)
29.05	3.0739	1.7	(2,-2,0,1)
30.42	2.9386	100.0	(1,1,-2,2)
30.53	2.9280	98.3	(1,-2,1,2)
30.55	2.9259	100.0	(2,-1,-1,2)

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Energy Properties

Formation Energy/atom

-0.82709

eV/atom

Energy/atom

-18.23988

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-18.2399

eV/atom

Volume/atom

16.40

Å³

c/a Ratio

1.2329

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0001

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

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

0.9911

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.2403

J/mol·K

Ω Parameter

1.5714

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

9.171%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3080

smaller = more stable mixing

VEC

5.077

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-7.025

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7150

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfmsn

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3295305

Reference Citation

The crystal structure and related material properties of ErPa(Al3Rh)3 were obtained from the Materials Project database (MP-ID: mp-3295305, 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_ErPa(Al3Rh)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.53480994
_cell_length_b   7.54365829
_cell_length_c   9.28977216
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   119.56353807
_symmetry_Int_Tables_number   1
_chemical_formula_structural   ErPa(Al3Rh)3
_chemical_formula_sum   'Er2 Pa2 Al18 Rh6'
_cell_volume   459.28611255
_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
  Er  Er0  1  0.67063525  0.99240327  0.75000000  1.0
  Er  Er1  1  0.32936475  0.00759673  0.25000000  1.0
  Pa  Pa2  1  0.99710838  0.67157649  0.75000000  1.0
  Pa  Pa3  1  0.00289162  0.32842351  0.25000000  1.0
  Al  Al4  1  0.13102029  0.12728604  0.75000000  1.0
  Al  Al5  1  0.86897971  0.87271396  0.25000000  1.0
  Al  Al6  1  0.00031562  0.33147621  0.57812870  1.0
  Al  Al7  1  0.99968438  0.66852379  0.42187130  1.0
  Al  Al8  1  0.99968438  0.66852379  0.07812870  1.0
  Al  Al9  1  0.33888436  0.00347936  0.92577623  1.0
  Al  Al10  1  0.00031562  0.33147621  0.92187130  1.0
  Al  Al11  1  0.66111564  0.99652064  0.07422377  1.0
  Al  Al12  1  0.66111564  0.99652064  0.42577623  1.0
  Al  Al13  1  0.33888436  0.00347936  0.57422377  1.0
  Al  Al14  1  0.33501095  0.33318529  0.04965487  1.0
  Al  Al15  1  0.66498905  0.66681471  0.95034513  1.0
  Al  Al16  1  0.66498905  0.66681471  0.54965487  1.0
  Al  Al17  1  0.33501095  0.33318529  0.45034513  1.0
  Al  Al18  1  0.34148830  0.54885339  0.75000000  1.0
  Al  Al19  1  0.65851170  0.45114661  0.25000000  1.0
  Al  Al20  1  0.55041073  0.34156974  0.75000000  1.0
  Al  Al21  1  0.44958927  0.65843026  0.25000000  1.0
  Rh  Rh22  1  0.67600191  0.32915170  0.49942739  1.0
  Rh  Rh23  1  0.32399809  0.67084830  0.50057261  1.0
  Rh  Rh24  1  0.32399809  0.67084830  0.99942739  1.0
  Rh  Rh25  1  0.67600191  0.32915170  0.00057261  1.0
  Rh  Rh26  1  0.00000000  0.00000000  0.50000000  1.0
  Rh  Rh27  1  0.00000000  0.00000000  0.00000000  1.0

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