K2SrNb3O9

高熵材料 HEA

MP-ID: mp-3295851 · Space group: P-3m1 (#164)

Materials Project API

Basic Information

Formula

K2SrNb3O9

MP-ID

mp-3295851

Elements

Sites

Density

4.9364

g/cm³

Volume

197.98

Å³

Cell a

5.7159

Cell b

5.7159

Cell c

6.9971

α Angle

90.00

β Angle

90.00

γ Angle

120.00

Space Group

P-3m1

Point Group

-3m

Crystal System

Trigonal

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
12.65	6.9971	3.5	(0,0,0,1)
17.92	4.9501	3.6	(1,0,-1,0)
17.92	4.9501	1.8	(0,1,-1,0)
22.00	4.0411	15.5	(1,0,-1,1)
22.00	4.0411	31.0	(1,-1,0,1)
31.30	2.8579	99.0	(2,-1,-1,0)
31.31	2.8570	100.0	(1,0,-1,2)
33.88	2.6458	1.8	(2,-1,-1,1)
40.77	2.2133	1.3	(2,-1,-1,2)
42.86	2.1099	1.4	(1,0,-1,3)
44.86	2.0205	76.7	(2,0,-2,2)
50.49	1.8075	3.1	(3,-1,-2,1)
50.49	1.8075	6.2	(3,-2,-1,1)
50.51	1.8070	8.3	(2,-1,-1,3)
55.71	1.6500	6.3	(3,0,-3,0)
55.71	1.6500	12.6	(3,-3,0,0)
55.71	1.6499	12.8	(3,-1,-2,2)
55.71	1.6499	25.6	(3,-2,-1,2)
55.73	1.6493	19.1	(1,0,-1,4)
65.30	1.4290	14.7	(4,-2,-2,0)
65.30	1.4290	7.3	(2,-4,2,0)
65.32	1.4285	22.0	(2,0,-2,4)
69.81	1.3472	1.6	(4,-1,-3,1)
69.81	1.3472	1.6	(3,-4,1,1)

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Energy Properties

Formation Energy/atom

-2.82650

eV/atom

Energy/atom

-13.16898

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-13.1690

eV/atom

Volume/atom

13.20

Å³

c/a Ratio

1.2242

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0007

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000000

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.600

Element Family

Metalloid-Nonmetal

Solute Fraction

0.400

Interstitial Fraction

0.000

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0776

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.9589

J/mol·K

Ω Parameter

0.0000

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

57.955%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.1070

smaller = more stable mixing

VEC

3.667

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.000

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7773

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfnnn

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3295851

Reference Citation

The crystal structure and related material properties of K2SrNb3O9 were obtained from the Materials Project database (MP-ID: mp-3295851, 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_K2SrNb3O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.71586679
_cell_length_b   5.71586614
_cell_length_c   6.99708798
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   119.99999811
_symmetry_Int_Tables_number   1
_chemical_formula_structural   K2SrNb3O9
_chemical_formula_sum   'K2 Sr1 Nb3 O9'
_cell_volume   197.97580780
_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
  K  K0  1  0.66666700  0.33333300  0.33549080  1.0
  K  K1  1  0.33333300  0.66666700  0.66450920  1.0
  Sr  Sr2  1  0.00000000  0.00000000  0.00000000  1.0
  Nb  Nb3  1  0.00000000  0.00000000  0.50000000  1.0
  Nb  Nb4  1  0.66666700  0.33333300  0.83085872  1.0
  Nb  Nb5  1  0.33333300  0.66666700  0.16914128  1.0
  O  O6  1  0.67201161  0.83600581  0.32755390  1.0
  O  O7  1  0.32798839  0.16399419  0.67244610  1.0
  O  O8  1  0.00000000  0.50000000  0.00000000  1.0
  O  O9  1  0.83600581  0.67201161  0.67244610  1.0
  O  O10  1  0.50000000  0.00000000  0.00000000  1.0
  O  O11  1  0.16399419  0.32798839  0.32755390  1.0
  O  O12  1  0.83600581  0.16399419  0.67244610  1.0
  O  O13  1  0.50000000  0.50000000  0.00000000  1.0
  O  O14  1  0.16399419  0.83600581  0.32755390  1.0

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