Nb3AlC2

High-Entropy Materials HEA Traditional Materials TRA Elasticity Data ELA

MP-ID: mp-996161 · Space group: P6_3/mmc (#194)

Materials Project API

Basic Information

Formula

Nb3AlC2

MP-ID

mp-996161

Elements

Sites

Density

6.7074

g/cm³

Volume

163.26

Å³

Cell a

3.1333

Cell b

3.1333

Cell c

19.2016

α Angle

90.00

β Angle

90.00

γ Angle

120.00

Space Group

P6_3/mmc

Point Group

6/mmm

Crystal System

Hexagonal

Bravais Lattice

Stability

Yes

Packing Fraction

0.7405

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
9.21	9.6008	62.3	(0,0,0,2)
18.48	4.8004	15.5	(0,0,0,4)
27.88	3.2003	15.2	(0,0,0,6)
33.35	2.6868	20.4	(1,0,-1,1)
33.35	2.6868	20.4	(0,1,-1,1)
33.35	2.6868	20.4	(1,-1,0,1)
34.34	2.6112	7.4	(1,0,-1,2)
34.34	2.6112	14.7	(1,-1,0,2)
35.95	2.4983	7.7	(1,0,-1,3)
35.95	2.4983	15.3	(1,-1,0,3)
37.47	2.4002	42.1	(0,0,0,8)
38.09	2.3622	50.0	(1,0,-1,4)
38.09	2.3622	100.0	(1,-1,0,4)
40.71	2.2161	22.0	(1,0,-1,5)
40.71	2.2161	44.0	(1,-1,0,5)
43.74	2.0697	1.5	(1,0,-1,6)
43.74	2.0697	3.0	(1,-1,0,6)
47.11	1.9291	2.4	(1,0,-1,7)
47.11	1.9291	4.9	(1,-1,0,7)
50.78	1.7978	1.8	(1,-1,0,8)
54.73	1.6772	10.3	(1,0,-1,9)
54.73	1.6772	20.7	(1,-1,0,9)
58.92	1.5674	4.2	(1,0,-1,10)
58.92	1.5674	8.5	(1,-1,0,10)

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Energy Properties

Formation Energy/atom

-0.52075

eV/atom

Energy/atom

-9.27266

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-17.3854

eV/atom

Volume/atom

13.60

Å³

c/a Ratio

6.1282

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

200.473

GPa

G_VRH

134.763

GPa

Young's Modulus E

330.281

GPa

Poisson Ratio ν

0.225

Pugh Ratio K/G

1.488

Vickers Hardness Est.

19.132

GPa

Ductility

Ductile

Anisotropy

0.095

Lame λ

110.631

GPa

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Nb · 0.500

Element Family

4d-TM

Solute Fraction

0.500

Interstitial Fraction

0.333

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0114

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.4088

J/mol·K

Ω Parameter

0.2861

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

26.278%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4467

smaller = more stable mixing

VEC

4.333

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-82.444

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9206

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.728

Family

Interstitial Alloy

Matrix Element

Nb · 0.500

Elasticity Features

Elastic Modulus Comparison (GPa)

Elastic Features

Elastic Anisotropy A^U

0.0950

Homogeneous Poisson ν

0.2250

Debye Temperature

618.7

Sound Velocity

4,962.3

m/s

Homogeneity

0.2250

Related Tasks

Related computation task IDs (3)

aaacesmc aaadtvkk aaaelrtw

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-996161

Reference Citation

The crystal structure and related material properties of Nb3AlC2 were obtained from the Materials Project database (MP-ID: mp-996161, 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_Nb3AlC2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.13331235
_cell_length_b   3.13331094
_cell_length_c   19.20158825
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   119.99998255
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Nb3AlC2
_chemical_formula_sum   'Nb6 Al2 C4'
_cell_volume   163.25821567
_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
  Nb  Nb0  1  0.66666700  0.33333300  0.36615946  1.0
  Nb  Nb1  1  0.33333300  0.66666700  0.86615946  1.0
  Nb  Nb2  1  0.33333300  0.66666700  0.63384054  1.0
  Nb  Nb3  1  0.66666700  0.33333300  0.13384054  1.0
  Nb  Nb4  1  -0.00000000  -0.00000000  0.50000000  1.0
  Nb  Nb5  1  -0.00000000  -0.00000000  -0.00000000  1.0
  Al  Al6  1  -0.00000000  -0.00000000  0.75000000  1.0
  Al  Al7  1  -0.00000000  -0.00000000  0.25000000  1.0
  C  C8  1  0.33333300  0.66666700  0.43054121  1.0
  C  C9  1  0.66666700  0.33333300  0.93054121  1.0
  C  C10  1  0.33333300  0.66666700  0.06945879  1.0
  C  C11  1  0.66666700  0.33333300  0.56945879  1.0

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