Ca3Ni7B2

High-Entropy Materials HEA Traditional Materials TRA Elasticity Data ELA

MP-ID: mp-8308 · Space group: R-3m (#166)

Materials Project API

Basic Information

Formula

Ca3Ni7B2

MP-ID

mp-8308

Elements

Sites

Density

5.7778

g/cm³

Volume

158.85

Å³

Cell a

7.6292

Cell b

7.6292

Cell c

7.6292

α Angle

39.10

β Angle

39.10

γ Angle

39.10

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
12.58	7.0368	20.1	(1,1,1)
20.52	4.3276	23.5	(0,1,0)
20.52	4.3276	46.9	(1,0,0)
25.31	3.5184	16.3	(2,2,2)
26.30	3.3893	1.1	(2,1,1)
29.25	3.0535	1.6	(2,2,1)
35.15	2.5528	6.6	(1,-1,0)
35.15	2.5528	3.3	(1,0,-1)
36.05	2.4914	15.5	(2,3,2)
36.05	2.4914	31.0	(3,2,2)
37.48	2.3997	15.3	(1,2,0)
37.48	2.3997	15.3	(2,0,1)
37.48	2.3997	15.3	(2,1,0)
38.38	2.3456	60.8	(3,3,3)
39.78	2.2659	84.0	(3,3,2)
41.05	2.1987	50.0	(1,-1,1)
41.05	2.1987	100.0	(1,1,-1)
41.74	2.1638	39.9	(0,2,0)
41.74	2.1638	79.9	(2,0,0)
43.82	2.0662	43.8	(2,3,1)
43.82	2.0662	65.7	(3,2,1)
43.82	2.0662	21.9	(1,2,3)
46.36	1.9585	11.4	(1,3,1)
46.36	1.9585	22.8	(3,1,1)

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Energy Properties

Formation Energy/atom

-0.33625

eV/atom

Energy/atom

-5.32263

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-10.2801

eV/atom

Volume/atom

13.24

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

0.0004

μB

Mag. Ordering

Unknown

Mag. Sites

Magnetization/Volume

0.000000

μB/Å³

Elastic Properties

K_VRH

102.596

GPa

G_VRH

50.245

GPa

Young's Modulus E

129.581

GPa

Poisson Ratio ν

0.289

Pugh Ratio K/G

2.042

Vickers Hardness Est.

5.579

GPa

Ductility

Brittle

Anisotropy

0.413

Lame λ

69.099

GPa

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Ni · 0.583

Element Family

3d-TM

Solute Fraction

0.417

Interstitial Fraction

0.167

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9596

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.9782

J/mol·K

Ω Parameter

0.3921

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

27.066%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4092

smaller = more stable mixing

VEC

6.833

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-34.147

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8735

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.730

Family

Ni-based Alloy

Matrix Element

Ni · 0.583

Elasticity Features

Elastic Modulus Comparison (GPa)

Elastic Features

Elastic Anisotropy A^U

0.4130

Homogeneous Poisson ν

0.2890

Debye Temperature

413.9

Sound Velocity

3,289.5

m/s

Homogeneity

0.2890

Related Tasks

Related computation task IDs (5)

aaadndkl aaadsrcc aaaemutj aaaetvxt aaafwyzl

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-8308

Reference Citation

The crystal structure and related material properties of Ca3Ni7B2 were obtained from the Materials Project database (MP-ID: mp-8308, 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

Loading 3D structure…

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Raw CIF Data

# generated using pymatgen
data_Ca3Ni7B2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.62919679
_cell_length_b   7.62919752
_cell_length_c   7.62919669
_cell_angle_alpha   39.09696772
_cell_angle_beta   39.09695376
_cell_angle_gamma   39.09696616
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca3Ni7B2
_chemical_formula_sum   'Ca3 Ni7 B2'
_cell_volume   158.84867784
_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  0.64502013  0.64502013  0.64502013  1.0
  Ca  Ca1  1  0.35497987  0.35497987  0.35497987  1.0
  Ca  Ca2  1  0.50000000  0.50000000  0.50000000  1.0
  Ni  Ni3  1  0.06028201  0.57309481  0.06028201  1.0
  Ni  Ni4  1  0.06028201  0.06028201  0.57309481  1.0
  Ni  Ni5  1  0.57309481  0.06028201  0.06028201  1.0
  Ni  Ni6  1  0.42690519  0.93971799  0.93971799  1.0
  Ni  Ni7  1  0.93971799  0.93971799  0.42690519  1.0
  Ni  Ni8  1  0.93971799  0.42690519  0.93971799  1.0
  Ni  Ni9  1  0.00000000  0.00000000  -0.00000000  1.0
  B  B10  1  0.83048755  0.83048755  0.83048755  1.0
  B  B11  1  0.16951245  0.16951245  0.16951245  1.0

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