Ca(FeSi)2

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1068250 · Space group: I4/mmm (#139)

Materials Project API

Basic Information

Formula

Ca(FeSi)2

MP-ID

mp-1068250

Elements

Sites

Density

4.4903

g/cm³

Volume

76.90

Å³

Cell a

5.6760

Cell b

5.6760

Cell c

5.6760

α Angle

139.34

β Angle

139.34

γ Angle

58.86

Space Group

I4/mmm

Point Group

4/mmm

Crystal System

Tetragonal

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 23)

2θ	d (Å)	I	hkl
17.94	4.9437	44.5	(1,1,-1)
32.10	2.7888	1.1	(1,-1,0)
35.50	2.5290	36.2	(2,1,-2)
36.35	2.4718	11.9	(2,2,-2)
37.01	2.4290	100.0	(2,0,-1)
46.03	1.9720	50.7	(1,-1,1)
49.26	1.8498	30.7	(3,1,-2)
49.78	1.8316	11.3	(2,0,-2)
51.71	1.7677	7.6	(3,2,-3)
55.79	1.6479	1.1	(3,3,-3)
59.44	1.5551	14.7	(3,0,-2)
60.01	1.5415	9.4	(3,1,-3)
65.83	1.4187	20.8	(4,2,-3)
67.13	1.3944	15.1	(2,-2,0)
70.12	1.3420	3.7	(3,-1,-1)
71.70	1.3163	5.4	(4,1,-3)
75.13	1.2645	1.6	(4,2,-4)
77.18	1.2359	4.8	(4,4,-4)
78.30	1.2211	3.2	(3,0,-3)
78.81	1.2145	3.7	(4,0,-2)
79.21	1.2093	17.7	(3,-1,-2)
87.63	1.1135	11.1	(4,0,-3)
89.53	1.0948	1.5	(4,1,-4)

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Energy Properties

Formation Energy/atom

-0.41952

eV/atom

Energy/atom

-6.37878

eV/atom

Energy above Hull

0.0099

eV/atom

Uncorrected Energy

-6.4072

eV/atom

Volume/atom

15.38

Å³

c/a Ratio

1.0000

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

1.2948

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.016840

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

0.400

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

0.4446

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

22.304%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.3474

smaller = more stable mixing

VEC

5.200

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-32.000

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9602

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.626

Family

Fe-rich Multi-Component

Matrix Element

Fe · 0.400

Related Tasks

Related computation task IDs (5)

aaaciukb aaadyksp aaaeusra aaafawpv aaafwxdy

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1068250

Reference Citation

The crystal structure and related material properties of Ca(FeSi)2 were obtained from the Materials Project database (MP-ID: mp-1068250, 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_Ca(FeSi)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.67600324
_cell_length_b   5.67600324
_cell_length_c   5.67600324
_cell_angle_alpha   139.34070985
_cell_angle_beta   139.34070985
_cell_angle_gamma   58.85571842
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca(FeSi)2
_chemical_formula_sum   'Ca1 Fe2 Si2'
_cell_volume   76.89629334
_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
  Ca  Ca0  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
  Si  Si3  1  0.63254000  0.63254000  0.00000000  1.0
  Si  Si4  1  0.36746000  0.36746000  0.00000000  1.0

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