NaCa2(SnAs)6

High-Entropy Materials HEA

MP-ID: mp-3292040 · Space group: C2/m (#12)

Materials Project API

Basic Information

Formula

NaCa2(SnAs)6

MP-ID

mp-3292040

Elements

Sites

Density

5.3811

g/cm³

Volume

390.35

Å³

Cell a

7.1197

Cell b

7.1197

Cell c

9.1986

α Angle

82.60

β Angle

82.60

γ Angle

119.96

Space Group

C2/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
9.95	8.8883	26.5	(0,0,1)
19.98	4.4442	11.9	(0,0,2)
25.89	3.4419	6.0	(1,1,0)
25.91	3.4391	12.1	(2,-1,1)
30.16	2.9629	50.1	(1,1,-1)
30.16	2.9628	4.7	(0,0,3)
30.19	2.9604	100.0	(2,-1,2)
34.48	2.6013	6.9	(2,-1,-2)
34.48	2.6010	3.4	(1,1,3)
40.60	2.2221	1.7	(0,0,4)
42.34	2.1345	32.0	(2,-1,-3)
42.35	2.1340	16.0	(1,1,4)
44.04	2.0561	19.1	(0,3,1)
44.04	2.0561	19.1	(3,0,1)
44.07	2.0549	19.0	(3,-3,0)
45.23	2.0046	4.2	(1,1,-3)
45.26	2.0034	8.3	(2,-1,4)
45.27	2.0030	1.6	(3,0,2)
45.30	2.0020	1.6	(3,-3,1)
48.79	1.8665	1.2	(0,3,-1)
48.79	1.8665	1.2	(3,0,-1)
48.81	1.8657	2.3	(3,0,3)
48.83	1.8651	2.3	(3,-3,2)
51.40	1.7777	6.1	(0,0,5)

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Energy Properties

Formation Energy/atom

-0.53031

eV/atom

Energy/atom

-17.48784

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-17.4878

eV/atom

Volume/atom

26.02

Å³

c/a Ratio

1.2920

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0024

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000010

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Sn · 0.400

Element Family

PostTransition-Noble

Solute Fraction

0.600

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1822

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.8290

J/mol·K

Ω Parameter

0.6600

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

20.062%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4485

smaller = more stable mixing

VEC

3.133

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-12.085

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8528

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfhwy

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3292040

Reference Citation

The crystal structure and related material properties of NaCa2(SnAs)6 were obtained from the Materials Project database (MP-ID: mp-3292040, 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_NaCa2(SnAs)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.11967652
_cell_length_b   7.11967721
_cell_length_c   9.19864046
_cell_angle_alpha   82.59653408
_cell_angle_beta   82.59653461
_cell_angle_gamma   119.95908424
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaCa2(SnAs)6
_chemical_formula_sum   'Na1 Ca2 Sn6 As6'
_cell_volume   390.34602470
_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
  Na  Na0  1  0.00000000  0.00000000  0.00000000  1.0
  Ca  Ca1  1  0.66668431  0.33331569  0.00000000  1.0
  Ca  Ca2  1  0.33331569  0.66668431  0.00000000  1.0
  Sn  Sn3  1  0.54331602  0.87746336  0.36744077  1.0
  Sn  Sn4  1  0.21138737  0.21138737  0.36832758  1.0
  Sn  Sn5  1  0.87746336  0.54331602  0.36744077  1.0
  Sn  Sn6  1  0.45668398  0.12253664  0.63255923  1.0
  Sn  Sn7  1  0.12253664  0.45668398  0.63255923  1.0
  Sn  Sn8  1  0.78861263  0.78861263  0.63167242  1.0
  As  As9  1  0.40565865  0.40565865  0.78792761  1.0
  As  As10  1  0.07071504  0.73602120  0.78811270  1.0
  As  As11  1  0.73602120  0.07071504  0.78811270  1.0
  As  As12  1  0.59434135  0.59434135  0.21207239  1.0
  As  As13  1  0.26397880  0.92928496  0.21188730  1.0
  As  As14  1  0.92928496  0.26397880  0.21188730  1.0

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