Sr2Cu2NiO7

High-Entropy Materials HEA

MP-ID: mp-1044112 · Space group: Ima2 (#46)

Materials Project API

Basic Information

Formula

Sr2Cu2NiO7

MP-ID

mp-1044112

Elements

Sites

Density

4.6930

g/cm³

Volume

334.74

Å³

Cell a

13.0790

Cell b

13.0790

Cell c

13.0790

α Angle

157.38

β Angle

157.09

γ Angle

32.42

Space Group

Ima2

Point Group

mm2

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
7.04	12.5592	7.2	(1,1,-1)
14.10	6.2796	17.9	(2,2,-2)
17.43	5.0878	3.6	(1,0,0)
20.11	4.4147	4.0	(2,1,-1)
21.22	4.1864	4.9	(3,3,-3)
24.38	3.6504	3.9	(0,0,1)
24.65	3.6115	3.4	(3,2,-2)
25.41	3.5053	28.2	(1,1,0)
28.28	3.1559	81.6	(2,2,-1)
28.43	3.1398	5.4	(4,4,-4)
30.27	2.9526	1.9	(4,3,-3)
32.54	2.7513	100.0	(3,3,-2)
34.53	2.5978	36.7	(1,-1,1)
34.98	2.5650	38.4	(1,-1,-1)
35.28	2.5439	2.5	(2,0,0)
35.73	2.5131	3.8	(0,2,0)
35.75	2.5118	38.7	(5,5,-5)
37.47	2.4005	2.3	(3,1,-1)
37.79	2.3804	31.4	(4,4,-3)
37.89	2.3745	2.0	(1,3,-1)
39.03	2.3078	2.0	(1,0,1)
40.38	2.2336	1.3	(2,1,0)
40.88	2.2073	4.2	(4,2,-2)
41.28	2.1871	3.6	(2,4,-2)

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Energy Properties

Formation Energy/atom

-1.51092

eV/atom

Energy/atom

-5.84418

eV/atom

Energy above Hull

0.1498

eV/atom

Uncorrected Energy

-5.2317

eV/atom

Volume/atom

13.95

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

6.3414

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.018940

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

O · 0.583

Element Family

Metalloid-Nonmetal

Solute Fraction

0.417

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1187

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.3012

J/mol·K

Ω Parameter

24.1632

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

52.713%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.9925

smaller = more stable mixing

VEC

5.333

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

0.222

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8070

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (2)

aaachkpz aaadzbge

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1044112

Reference Citation

The crystal structure and related material properties of Sr2Cu2NiO7 were obtained from the Materials Project database (MP-ID: mp-1044112, 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_Sr2Cu2NiO7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.07902448
_cell_length_b   13.07902448
_cell_length_c   13.07902448
_cell_angle_alpha   157.38031136
_cell_angle_beta   157.08732052
_cell_angle_gamma   32.41609454
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Sr2Cu2NiO7
_chemical_formula_sum   'Sr4 Cu4 Ni2 O14'
_cell_volume   334.74021680
_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
  Sr  Sr0  1  0.14634000  0.62862100  0.47268000  1.0
  Sr  Sr1  1  0.85366000  0.32634000  0.48228200  1.0
  Sr  Sr2  1  0.65594100  0.12862100  0.48228200  1.0
  Sr  Sr3  1  0.34405900  0.82634000  0.47268000  1.0
  Cu  Cu4  1  0.06033700  0.03839100  0.97912400  1.0
  Cu  Cu5  1  0.93966300  0.91878700  0.97805400  1.0
  Cu  Cu6  1  0.55926700  0.53839100  0.97805400  1.0
  Cu  Cu7  1  0.44073300  0.41878700  0.97912400  1.0
  Ni  Ni8  1  0.67735000  0.78162300  0.95897300  1.0
  Ni  Ni9  1  0.32265000  0.28162300  0.10427300  1.0
  O  O10  1  0.33661600  0.64760000  0.48421600  1.0
  O  O11  1  0.66338400  0.14760000  0.31098400  1.0
  O  O12  1  0.82564700  0.30445000  0.97866100  1.0
  O  O13  1  0.17435300  0.15301400  0.47880400  1.0
  O  O14  1  0.82578900  0.80445000  0.47880400  1.0
  O  O15  1  0.17421100  0.65301400  0.97866100  1.0
  O  O16  1  0.32533800  0.80494100  0.97686600  1.0
  O  O17  1  0.67466200  0.65152800  0.47960300  1.0
  O  O18  1  0.32807500  0.30494100  0.47960300  1.0
  O  O19  1  0.67192500  0.15152800  0.97686600  1.0
  O  O20  1  0.69842900  0.64910000  0.98520400  1.0
  O  O21  1  0.30157100  0.28677600  0.95067200  1.0
  O  O22  1  0.16389600  0.14910000  0.95067200  1.0
  O  O23  1  0.83610400  0.78677600  0.98520400  1.0

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