TmPa(CoSi2)2

High-Entropy Materials HEA

MP-ID: mp-3249488 · Space group: Amm2 (#38)

Materials Project API

Basic Information

Formula

TmPa(CoSi2)2

MP-ID

mp-3249488

Elements

Sites

Density

8.3158

g/cm³

Volume

125.84

Å³

Cell a

8.3723

Cell b

8.3723

Cell c

3.9264

α Angle

90.00

β Angle

90.00

γ Angle

152.79

Space Group

Amm2

Point Group

mm2

Crystal System

Orthorhombic

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 24)

2θ	d (Å)	I	hkl
10.87	8.1374	7.0	(1,-1,0)
21.84	4.0687	45.7	(2,-2,0)
22.65	3.9264	1.4	(0,0,1)
23.24	3.8280	32.0	(1,0,0)
25.18	3.5363	45.4	(1,-1,1)
28.00	3.1872	3.2	(1,-2,0)
28.00	3.1872	3.2	(2,-1,0)
31.67	2.8253	21.8	(2,-2,1)
32.67	2.7409	74.9	(1,0,1)
33.02	2.7125	5.7	(3,-3,0)
35.79	2.5090	34.0	(2,-3,0)
35.79	2.5090	34.0	(3,-2,0)
36.30	2.4745	100.0	(2,-1,1)
40.42	2.2317	36.6	(3,-3,1)
42.77	2.1142	6.9	(2,-3,1)
42.77	2.1142	6.9	(3,-2,1)
44.54	2.0343	3.0	(4,-4,0)
46.09	1.9693	27.9	(1,1,0)
46.24	1.9632	27.7	(0,0,2)
50.53	1.8063	17.8	(4,-4,1)
51.22	1.7836	6.0	(4,-3,1)
51.56	1.7726	10.0	(3,-1,0)
51.70	1.7681	9.9	(2,-2,2)
52.38	1.7469	8.2	(1,0,2)

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Energy Properties

Formation Energy/atom

-0.73673

eV/atom

Energy/atom

-22.42930

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-22.4293

eV/atom

Volume/atom

15.73

Å³

c/a Ratio

0.4690

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0000

μB

Mag. Ordering

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

Si · 0.500

Element Family

Metalloid-Nonmetal

Solute Fraction

0.500

Interstitial Fraction

0.500

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.2130

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

10.0849

J/mol·K

Ω Parameter

1.0044

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

18.852%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.2331

smaller = more stable mixing

VEC

6.714

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-17.500

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8750

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahcwyi

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3249488

Reference Citation

The crystal structure and related material properties of TmPa(CoSi2)2 were obtained from the Materials Project database (MP-ID: mp-3249488, 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_TmPa(CoSi2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.37224937
_cell_length_b   8.37224992
_cell_length_c   3.92637826
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   152.79158988
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TmPa(CoSi2)2
_chemical_formula_sum   'Tm1 Pa1 Co2 Si4'
_cell_volume   125.83740232
_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
  Tm  Tm0  1  0.39270472  0.60729528  0.75000000  1.0
  Pa  Pa1  1  0.60967665  0.39032335  0.25000000  1.0
  Co  Co2  1  0.82198245  0.17801755  0.25000000  1.0
  Co  Co3  1  0.17421342  0.82578658  0.75000000  1.0
  Si  Si4  1  0.95834602  0.04165398  0.25000000  1.0
  Si  Si5  1  0.03931181  0.96068819  0.75000000  1.0
  Si  Si6  1  0.25222617  0.74777383  0.25000000  1.0
  Si  Si7  1  0.75153976  0.24846024  0.75000000  1.0

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