Th2Si6Pd20Rh

High-Entropy Materials HEA

MP-ID: mp-3294296 · Space group: R3m (#160)

Materials Project API

Basic Information

Formula

Th2Si6Pd20Rh

MP-ID

mp-3294296

Elements

Sites

Density

10.4551

g/cm³

Volume

454.86

Å³

Cell a

8.6226

Cell b

8.6226

Cell c

8.6422

α Angle

60.08

β Angle

60.08

γ Angle

60.00

Space Group

R3m

Point Group

Crystal System

Trigonal

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
14.51	6.1040	14.6	(1,1,0)
20.55	4.3211	3.1	(1,1,2)
20.60	4.3113	3.1	(2,1,1)
24.18	3.6801	2.1	(2,1,2)
32.78	2.7323	43.7	(2,1,3)
32.84	2.7273	35.4	(3,2,1)
32.84	2.7273	7.1	(2,-1,1)
35.97	2.4967	22.0	(1,0,3)
36.06	2.4910	44.5	(3,2,3)
36.08	2.4891	22.1	(3,3,2)
38.22	2.3548	22.6	(0,0,3)
38.27	2.3516	24.9	(2,0,3)
38.31	2.3492	39.2	(3,1,3)
38.34	2.3477	100.0	(3,3,3)
41.81	2.1606	37.3	(2,2,4)
41.91	2.1557	36.8	(4,2,2)
43.81	2.0666	16.6	(2,1,4)
43.85	2.0645	11.0	(3,2,4)
43.91	2.0618	12.4	(4,2,3)
43.93	2.0613	14.0	(4,3,2)
44.53	2.0347	9.5	(3,3,4)
47.05	1.9316	3.5	(1,3,4)
47.05	1.9316	1.7	(3,1,4)
47.11	1.9290	5.9	(4,3,1)

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Energy Properties

Formation Energy/atom

-0.75582

eV/atom

Energy/atom

-24.30543

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-24.3054

eV/atom

Volume/atom

15.68

Å³

c/a Ratio

1.0023

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0006

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

Pd · 0.690

Element Family

4d-TM

Solute Fraction

0.310

Interstitial Fraction

0.207

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.8828

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.3393

J/mol·K

Ω Parameter

1.0419

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

10.651%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.2449

smaller = more stable mixing

VEC

8.172

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-12.910

kJ/mol; negative = exothermic mixing

Entropy Norm

0.6368

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahflfs

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3294296

Reference Citation

The crystal structure and related material properties of Th2Si6Pd20Rh were obtained from the Materials Project database (MP-ID: mp-3294296, 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_Th2Si6Pd20Rh
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.62260050
_cell_length_b   8.62260065
_cell_length_c   8.64222482
_cell_angle_alpha   60.07508509
_cell_angle_beta   60.07508688
_cell_angle_gamma   59.99999814
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Th2Si6Pd20Rh
_chemical_formula_sum   'Th2 Si6 Pd20 Rh1'
_cell_volume   454.86136807
_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
  Th  Th0  1  0.74479168  0.74479168  0.76562395  1.0
  Th  Th1  1  0.25041821  0.25041821  0.24874437  1.0
  Si  Si2  1  0.73412834  0.73412834  0.26297006  1.0
  Si  Si3  1  0.26877225  0.73412834  0.26297006  1.0
  Si  Si4  1  0.73412834  0.26877225  0.26297006  1.0
  Si  Si5  1  0.26227641  0.26227641  0.73738655  1.0
  Si  Si6  1  0.73805962  0.26227641  0.73738655  1.0
  Si  Si7  1  0.26227641  0.73805962  0.73738655  1.0
  Pd  Pd8  1  0.00141335  0.00141335  0.99575995  1.0
  Pd  Pd9  1  0.61593865  0.15237912  0.61574159  1.0
  Pd  Pd10  1  0.15237912  0.61593865  0.61574159  1.0
  Pd  Pd11  1  0.61593865  0.61593865  0.61574159  1.0
  Pd  Pd12  1  0.38520915  0.38520915  0.84437456  1.0
  Pd  Pd13  1  0.38364642  0.84649372  0.38621444  1.0
  Pd  Pd14  1  0.84649372  0.38364642  0.38621444  1.0
  Pd  Pd15  1  0.38364642  0.38364642  0.38621444  1.0
  Pd  Pd16  1  0.99970088  0.99970088  0.34338203  1.0
  Pd  Pd17  1  0.65721520  0.99970088  0.34338203  1.0
  Pd  Pd18  1  0.99970088  0.65721520  0.34338203  1.0
  Pd  Pd19  1  0.65405930  0.34421555  0.00038170  1.0
  Pd  Pd20  1  0.00134444  0.34421555  0.00038170  1.0
  Pd  Pd21  1  0.00109840  0.34647626  0.65132693  1.0
  Pd  Pd22  1  0.34421555  0.65405930  0.00038170  1.0
  Pd  Pd23  1  0.34647626  0.00109840  0.65132693  1.0
  Pd  Pd24  1  0.34421555  0.00134444  0.00038170  1.0
  Pd  Pd25  1  0.00109840  0.00109840  0.65132693  1.0
  Pd  Pd26  1  0.00134444  0.65405930  0.00038170  1.0
  Pd  Pd27  1  0.65405930  0.00134444  0.00038170  1.0
  Rh  Rh28  1  0.61595161  0.61595161  0.15214316  1.0

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