Ho9Sc(Si3O)2

High-Entropy Materials HEA

MP-ID: mp-3296784 · Space group: P312 (#149)

Materials Project API

Basic Information

Formula

Ho9Sc(Si3O)2

MP-ID

mp-3296784

Elements

Sites

Density

7.9055

g/cm³

Volume

363.35

Å³

Cell a

8.2839

Cell b

8.2839

Cell c

6.1139

α Angle

90.00

β Angle

90.00

γ Angle

120.00

Space Group

P312

Point Group

Crystal System

Trigonal

Bravais Lattice

Stability

Yes

Packing Fraction

0.7405

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
12.34	7.1741	13.5	(1,0,-1,0)
14.49	6.1139	1.2	(0,0,0,1)
19.07	4.6533	5.5	(1,0,-1,1)
21.45	4.1420	9.4	(2,-1,-1,0)
24.82	3.5871	22.4	(2,0,-2,0)
25.98	3.4291	41.2	(2,-1,-1,1)
28.86	3.0939	2.0	(2,0,-2,1)
29.21	3.0570	8.1	(0,0,0,2)
31.82	2.8123	41.8	(1,0,-1,2)
33.04	2.7116	7.1	(2,-3,1,0)
33.04	2.7116	35.4	(3,-1,-2,0)
36.24	2.4787	100.0	(3,-1,-2,1)
36.53	2.4596	61.8	(2,-1,-1,2)
37.61	2.3914	21.5	(3,0,-3,0)
43.71	2.0710	1.1	(4,-2,-2,0)
44.67	2.0285	1.7	(3,-2,-1,2)
44.67	2.0285	1.7	(3,-1,-2,2)
46.29	1.9615	5.9	(4,-2,-2,1)
48.09	1.8921	1.2	(4,-1,-3,1)
48.32	1.8835	4.7	(3,0,-3,2)
49.87	1.8286	7.2	(2,-1,-1,3)
50.91	1.7935	6.5	(4,0,-4,0)
53.44	1.7146	7.4	(2,-4,2,2)
53.44	1.7146	14.8	(4,-2,-2,2)

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Energy Properties

Formation Energy/atom

-1.40637

eV/atom

Energy/atom

-22.06850

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-22.0685

eV/atom

Volume/atom

20.19

Å³

c/a Ratio

0.7381

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.3456

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000950

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Ho · 0.500

Element Family

Lanthanide

Solute Fraction

0.500

Interstitial Fraction

0.333

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1175

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.2908

J/mol·K

Ω Parameter

4.6772

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

27.443%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.6831

smaller = more stable mixing

VEC

7.444

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-3.052

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8061

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfoxk

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3296784

Reference Citation

The crystal structure and related material properties of Ho9Sc(Si3O)2 were obtained from the Materials Project database (MP-ID: mp-3296784, 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_Ho9Sc(Si3O)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.28393593
_cell_length_b   8.28393613
_cell_length_c   6.11393899
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   120.00000312
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ho9Sc(Si3O)2
_chemical_formula_sum   'Ho9 Sc1 Si6 O2'
_cell_volume   363.35002298
_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
  Ho  Ho0  1  0.23170326  0.99924686  0.25141876  1.0
  Ho  Ho1  1  0.76754360  0.99924686  0.74858124  1.0
  Ho  Ho2  1  0.00075314  0.23245640  0.25141876  1.0
  Ho  Ho3  1  0.00075314  0.76829674  0.74858124  1.0
  Ho  Ho4  1  0.76754360  0.76829674  0.25141876  1.0
  Ho  Ho5  1  0.23170326  0.23245640  0.74858124  1.0
  Ho  Ho6  1  0.33333300  0.66666700  0.00000000  1.0
  Ho  Ho7  1  0.66666700  0.33333300  0.00000000  1.0
  Ho  Ho8  1  0.66666700  0.33333300  0.50000000  1.0
  Sc  Sc9  1  0.33333300  0.66666700  0.50000000  1.0
  Si  Si10  1  0.59841605  0.99621942  0.25713629  1.0
  Si  Si11  1  0.39780336  0.99621942  0.74286371  1.0
  Si  Si12  1  0.00378058  0.60219664  0.25713629  1.0
  Si  Si13  1  0.00378058  0.40158395  0.74286371  1.0
  Si  Si14  1  0.39780336  0.40158395  0.25713629  1.0
  Si  Si15  1  0.59841605  0.60219664  0.74286371  1.0
  O  O16  1  0.00000000  0.00000000  0.00000000  1.0
  O  O17  1  0.00000000  0.00000000  0.50000000  1.0

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