Li2Cu2F7

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-863404 · Space group: Fd-3m (#227)

Materials Project API

Basic Information

Formula

Li2Cu2F7

MP-ID

mp-863404

Elements

Sites

Density

3.6049

g/cm³

Volume

252.40

Å³

Cell a

7.0936

Cell b

7.0936

Cell c

7.0936

α Angle

60.00

β Angle

60.00

γ Angle

60.00

Space Group

Fd-3m

Point Group

m-3m

Crystal System

Cubic

Bravais Lattice

Stability

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 21)

2θ	d (Å)	I	hkl
15.30	5.7919	100.0	(1,1,1)
29.53	3.0247	79.8	(2,2,1)
30.88	2.8959	74.2	(2,2,2)
35.80	2.5080	2.0	(2,2,0)
39.14	2.3015	1.4	(3,2,2)
44.23	2.0477	3.1	(3,3,2)
47.07	1.9306	22.6	(3,3,3)
51.53	1.7734	60.2	(4,2,2)
54.08	1.6957	15.8	(4,3,2)
58.16	1.5862	1.3	(4,3,1)
60.52	1.5298	10.5	(4,4,3)
61.29	1.5124	28.3	(4,4,2)
64.34	1.4480	3.1	(4,4,4)
66.57	1.4047	12.6	(5,3,3)
72.35	1.3060	18.4	(5,3,1)
75.87	1.2540	6.8	(4,4,0)
81.40	1.1823	2.5	(6,3,3)
83.44	1.1584	4.4	(6,4,3)
84.12	1.1507	10.6	(6,4,4)
86.84	1.1216	5.6	(6,4,2)
88.87	1.1011	3.8	(6,5,4)

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Energy Properties

Formation Energy/atom

-2.22798

eV/atom

Energy/atom

-4.53873

eV/atom

Energy above Hull

0.0696

eV/atom

Uncorrected Energy

-4.2447

eV/atom

Volume/atom

11.47

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

6.0008

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.023780

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

F · 0.636

Element Family

Metalloid-Nonmetal

Solute Fraction

0.364

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9075

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.5452

J/mol·K

Ω Parameter

3.4566

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

53.060%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

1.2529

smaller = more stable mixing

VEC

5.364

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-0.793

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8261

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.555

Family

F-rich Multi-Component

Matrix Element

F · 0.636

Related Tasks

Related computation task IDs (2)

aaabxzhe aaadxcxb

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-863404

Reference Citation

The crystal structure and related material properties of Li2Cu2F7 were obtained from the Materials Project database (MP-ID: mp-863404, 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_Li2Cu2F7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.09358492
_cell_length_b   7.09358492
_cell_length_c   7.09358492
_cell_angle_alpha   60.00000000
_cell_angle_beta   60.00000000
_cell_angle_gamma   60.00000000
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Li2Cu2F7
_chemical_formula_sum   'Li4 Cu4 F14'
_cell_volume   252.39591338
_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
  Li  Li0  1  0.12500000  0.12500000  0.62500000  1.0
  Li  Li1  1  0.12500000  0.62500000  0.12500000  1.0
  Li  Li2  1  0.12500000  0.12500000  0.12500000  1.0
  Li  Li3  1  0.62500000  0.12500000  0.12500000  1.0
  Cu  Cu4  1  0.12500000  0.62500000  0.62500000  1.0
  Cu  Cu5  1  0.62500000  0.62500000  0.62500000  1.0
  Cu  Cu6  1  0.62500000  0.12500000  0.62500000  1.0
  Cu  Cu7  1  0.62500000  0.62500000  0.12500000  1.0
  F  F8  1  0.29621000  0.70379000  0.70379000  1.0
  F  F9  1  0.70379000  0.29621000  0.70379000  1.0
  F  F10  1  0.29621000  0.29621000  0.70379000  1.0
  F  F11  1  0.54621000  0.95379000  0.95379000  1.0
  F  F12  1  0.70379000  0.70379000  0.29621000  1.0
  F  F13  1  0.00000000  0.00000000  0.00000000  1.0
  F  F14  1  0.95379000  0.54621000  0.95379000  1.0
  F  F15  1  0.29621000  0.70379000  0.29621000  1.0
  F  F16  1  0.25000000  0.25000000  0.25000000  1.0
  F  F17  1  0.54621000  0.54621000  0.95379000  1.0
  F  F18  1  0.70379000  0.29621000  0.29621000  1.0
  F  F19  1  0.95379000  0.95379000  0.54621000  1.0
  F  F20  1  0.54621000  0.95379000  0.54621000  1.0
  F  F21  1  0.95379000  0.54621000  0.54621000  1.0

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