K(FeS)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1070151 · Space group: I4/mmm (#139)

Materials Project API

Basic Information

Formula

K(FeS)2

MP-ID

mp-1070151

Elements

Sites

Density

4.2428

g/cm³

Volume

84.11

Å³

Cell a

6.8305

Cell b

6.8305

Cell c

6.8305

α Angle

149.03

β Angle

149.03

γ Angle

44.36

Space Group

I4/mmm

Point Group

4/mmm

Crystal System

Tetragonal

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 22)

2θ	d (Å)	I	hkl
14.00	6.3251	100.0	(1,1,-1)
28.22	3.1625	21.3	(2,2,-2)
32.46	2.7583	51.2	(2,1,-1)
37.67	2.3878	52.1	(1,1,0)
43.54	2.0787	1.1	(3,2,-2)
45.38	1.9985	25.3	(2,2,-1)
50.02	1.8234	30.4	(1,-1,1)
52.21	1.7520	11.8	(2,0,0)
56.37	1.6322	39.8	(3,3,-2)
58.36	1.5813	4.3	(4,4,-4)
58.42	1.5796	9.6	(3,1,-1)
60.91	1.5211	13.6	(2,1,0)
69.77	1.3480	3.0	(4,4,-3)
72.00	1.3115	3.5	(5,4,-4)
73.44	1.2893	8.8	(0,0,2)
75.09	1.2650	1.6	(5,5,-5)
75.21	1.2633	3.7	(1,1,1)
80.38	1.1946	6.2	(5,3,-3)
80.44	1.1939	3.3	(2,2,0)
82.60	1.1680	2.8	(3,0,0)
85.50	1.1357	2.1	(5,5,-4)
85.61	1.1345	7.7	(2,0,1)

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Energy Properties

Formation Energy/atom

-0.87090

eV/atom

Energy/atom

-6.14014

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-10.7569

eV/atom

Volume/atom

16.82

Å³

c/a Ratio

1.0000

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

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Fe · 0.400

Element Family

3d-TM

Solute Fraction

0.600

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.0549

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.7706

J/mol·K

Ω Parameter

0.4326

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

32.032%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6476

smaller = more stable mixing

VEC

5.800

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-19.200

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9602

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.553

Family

Fe-rich Multi-Component

Matrix Element

Fe · 0.400

Related Tasks

Related computation task IDs (5)

aaacixdx aaadwmak aaaemgsl aaaetclv aaafjbqa

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1070151

Reference Citation

The crystal structure and related material properties of K(FeS)2 were obtained from the Materials Project database (MP-ID: mp-1070151, 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_K(FeS)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.83049696
_cell_length_b   6.83049696
_cell_length_c   6.83049696
_cell_angle_alpha   149.03494326
_cell_angle_beta   149.03494326
_cell_angle_gamma   44.35987400
_symmetry_Int_Tables_number   1
_chemical_formula_structural   K(FeS)2
_chemical_formula_sum   'K1 Fe2 S2'
_cell_volume   84.11456897
_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  0.00000000  -0.00000000  0.00000000  1.0
  Fe  Fe1  1  0.75000000  0.25000000  0.50000000  1.0
  Fe  Fe2  1  0.25000000  0.75000000  0.50000000  1.0
  S  S3  1  0.65774162  0.65774162  0.00000000  1.0
  S  S4  1  0.34225838  0.34225838  -0.00000000  1.0

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