Ca9Pd5Au

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-3292938 · Space group: P1 (#1)

Materials Project API

Basic Information

Formula

Ca9Pd5Au

MP-ID

mp-3292938

Elements

Sites

Density

4.5930

g/cm³

Volume

393.99

Å³

Cell a

7.6955

Cell b

7.6542

Cell c

7.6765

α Angle

71.72

β Angle

71.14

γ Angle

71.28

Space Group

Point Group

Crystal System

Triclinic

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
12.53	7.0626	14.3	(0,0,1)
12.53	7.0617	63.6	(1,0,0)
12.56	7.0476	79.3	(0,1,0)
15.39	5.7564	8.6	(1,0,1)
15.44	5.7388	2.6	(1,1,0)
15.54	5.7005	14.7	(0,1,1)
15.62	5.6722	47.0	(1,1,1)
19.77	4.4906	51.4	(0,1,-1)
19.85	4.4718	29.3	(1,-1,0)
19.86	4.4711	52.7	(1,0,-1)
23.46	3.7921	14.1	(1,-1,1)
23.49	3.7866	30.8	(1,1,-1)
23.64	3.7643	26.7	(1,-1,-1)
23.79	3.7399	1.8	(2,1,1)
23.86	3.7295	2.9	(1,1,2)
23.92	3.7203	3.8	(1,2,1)
25.22	3.5313	10.6	(0,0,2)
25.22	3.5308	3.9	(2,0,0)
25.25	3.5267	20.1	(1,0,2)
25.26	3.5264	43.4	(2,0,1)
25.27	3.5238	12.5	(0,2,0)
25.30	3.5201	17.5	(2,1,0)
25.34	3.5149	44.8	(1,2,0)
25.43	3.5026	40.7	(0,1,2)

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Energy Properties

Formation Energy/atom

-0.63984

eV/atom

Energy/atom

-15.88863

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-15.8886

eV/atom

Volume/atom

26.27

Å³

c/a Ratio

0.9975

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0022

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000010

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Ca · 0.600

Element Family

Alkali-AlkEarth

Solute Fraction

0.400

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.8532

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

7.0938

J/mol·K

Ω Parameter

0.1551

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

16.643%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6208

smaller = more stable mixing

VEC

5.267

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-62.555

kJ/mol; negative = exothermic mixing

Entropy Norm

0.7766

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.607

Family

Ca-rich Multi-Component

Matrix Element

Ca · 0.600

Related Tasks

Related computation task IDs (1)

aaahfjfm

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3292938

Reference Citation

The crystal structure and related material properties of Ca9Pd5Au were obtained from the Materials Project database (MP-ID: mp-3292938, 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_Ca9Pd5Au
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.69551615
_cell_length_b   7.65414619
_cell_length_c   7.67646395
_cell_angle_alpha   71.72485313
_cell_angle_beta   71.14446351
_cell_angle_gamma   71.27793397
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca9Pd5Au
_chemical_formula_sum   'Ca9 Pd5 Au1'
_cell_volume   393.99303254
_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  0.99890281  0.00013845  0.00266302  1.0
  Ca  Ca1  1  0.79366821  0.79596874  0.79836503  1.0
  Ca  Ca2  1  0.20238803  0.20574924  0.19672960  1.0
  Ca  Ca3  1  0.33426463  0.60072763  0.84800421  1.0
  Ca  Ca4  1  0.84038590  0.33458917  0.60535005  1.0
  Ca  Ca5  1  0.60518410  0.84445050  0.33023955  1.0
  Ca  Ca6  1  0.66852485  0.39558409  0.15773751  1.0
  Ca  Ca7  1  0.15502907  0.66343153  0.39246755  1.0
  Ca  Ca8  1  0.39889914  0.15818638  0.67085662  1.0
  Pd  Pd9  1  0.58832038  0.15474510  0.95717573  1.0
  Pd  Pd10  1  0.95623339  0.58817705  0.15061122  1.0
  Pd  Pd11  1  0.84397902  0.04360117  0.41433121  1.0
  Pd  Pd12  1  0.41220887  0.84547208  0.04621418  1.0
  Pd  Pd13  1  0.04402211  0.41367186  0.84329925  1.0
  Au  Au14  1  0.15798850  0.95550502  0.58595628  1.0

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