Ca2B4Rh5

High-Entropy Materials HEA Traditional Materials TRA Elasticity Data ELA

MP-ID: mp-8895 · Space group: Fmmm (#69)

Materials Project API

Basic Information

Formula

Ca2B4Rh5

MP-ID

mp-8895

Elements

Sites

Density

7.0603

g/cm³

Volume

150.04

Å³

Cell a

5.4707

Cell b

5.6062

Cell c

6.2363

α Angle

77.64

β Angle

63.98

γ Angle

60.80

Space Group

Fmmm

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
15.81	5.6044	15.6	(0,0,1)
18.13	4.8936	100.0	(0,1,0)
20.21	4.3932	16.4	(1,1,1)
20.21	4.3932	5.5	(1,0,1)
24.14	3.6861	12.7	(0,1,1)
30.38	2.9426	12.8	(1,1,2)
30.38	2.9426	38.4	(1,0,-1)
31.94	2.8022	69.2	(0,0,2)
32.74	2.7354	14.6	(2,1,1)
36.55	2.4582	4.0	(2,1,0)
36.73	2.4468	94.6	(0,2,0)
36.97	2.4317	76.2	(0,1,2)
37.67	2.3877	89.9	(2,2,1)
37.67	2.3877	89.9	(2,0,1)
40.22	2.2424	3.3	(0,2,1)
40.23	2.2416	26.0	(1,2,2)
40.23	2.2416	8.7	(1,-1,2)
41.09	2.1966	4.6	(2,2,2)
41.09	2.1966	1.5	(2,0,2)
44.66	2.0293	8.3	(1,1,3)
46.39	1.9574	48.3	(2,1,-1)
48.75	1.8681	3.1	(0,0,3)
49.45	1.8431	25.3	(0,2,2)
49.45	1.8431	25.3	(0,2,-2)

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Energy Properties

Formation Energy/atom

-0.61411

eV/atom

Energy/atom

-6.75504

eV/atom

Energy above Hull

0.0015

eV/atom

Uncorrected Energy

-15.6111

eV/atom

Volume/atom

13.64

Å³

c/a Ratio

1.1399

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

0.0000

μB

Mag. Ordering

Unknown

Mag. Sites

Magnetization/Volume

0.000000

μB/Å³

Elastic Properties

K_VRH

156.278

GPa

G_VRH

81.829

GPa

Young's Modulus E

209.007

GPa

Poisson Ratio ν

0.277

Pugh Ratio K/G

1.910

Vickers Hardness Est.

9.340

GPa

Ductility

Brittle

Anisotropy

0.348

Lame λ

101.725

GPa

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Rh · 0.455

Element Family

4d-TM

Solute Fraction

0.545

Interstitial Fraction

0.364

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0362

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.6150

J/mol·K

Ω Parameter

0.7933

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

28.955%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4652

smaller = more stable mixing

VEC

5.545

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-22.520

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9432

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.493

Family

Rh-rich Multi-Component

Matrix Element

Rh · 0.455

Elasticity Features

Elastic Modulus Comparison (GPa)

Elastic Features

Elastic Anisotropy A^U

0.3480

Homogeneous Poisson ν

0.2770

Debye Temperature

472.4

Sound Velocity

3,791.8

m/s

Homogeneity

0.2770

Related Tasks

Related computation task IDs (5)

aaadmxmv aaadstjd aaaelmjg aaaeubug aaafseyb

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-8895

Reference Citation

The crystal structure and related material properties of Ca2B4Rh5 were obtained from the Materials Project database (MP-ID: mp-8895, 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_Ca2B4Rh5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.47071587
_cell_length_b   5.60617611
_cell_length_c   6.23626019
_cell_angle_alpha   77.64244182
_cell_angle_beta   63.98403930
_cell_angle_gamma   60.79611670
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca2B4Rh5
_chemical_formula_sum   'Ca2 B4 Rh5'
_cell_volume   150.03594167
_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  0.14254584  -0.00000000  0.71491032  1.0
  Ca  Ca1  1  0.85745416  0.00000000  0.28508968  1.0
  B  B2  1  0.20872831  0.32130131  0.26124407  1.0
  B  B3  1  0.79127169  0.67869869  0.73875593  1.0
  B  B4  1  0.46997138  0.32130131  0.73875593  1.0
  B  B5  1  0.53002862  0.67869869  0.26124407  1.0
  Rh  Rh6  1  0.50000000  0.00000000  0.00000000  1.0
  Rh  Rh7  1  0.50000000  0.50000000  0.00000000  1.0
  Rh  Rh8  1  0.00000000  0.50000000  0.00000000  1.0
  Rh  Rh9  1  0.25000000  0.50000000  0.50000000  1.0
  Rh  Rh10  1  0.75000000  0.50000000  0.50000000  1.0

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