Ac2BeSi8Ni17

High-Entropy Materials HEA

MP-ID: mp-3292870 · Space group: Fmmm (#69)

Materials Project API

Basic Information

Formula

Ac2BeSi8Ni17

MP-ID

mp-3292870

Elements

Sites

Density

8.0317

g/cm³

Volume

348.47

Å³

Cell a

7.9969

Cell b

7.8971

Cell c

7.8102

α Angle

61.21

β Angle

59.93

γ Angle

58.86

Space Group

Fmmm

Point Group

mmm

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
13.74	6.4469	3.8	(1,0,0)
13.74	6.4469	1.3	(0,0,1)
15.51	5.7147	11.8	(1,1,0)
15.84	5.5940	13.4	(1,0,1)
16.26	5.4504	9.3	(0,1,1)
22.24	3.9975	23.1	(0,1,-1)
22.54	3.9441	10.6	(1,2,1)
22.54	3.9441	10.6	(1,0,-1)
22.78	3.9038	45.7	(1,-1,0)
26.44	3.3715	6.0	(1,-1,1)
26.95	3.3080	26.6	(0,2,1)
27.67	3.2235	24.7	(0,2,0)
27.67	3.2235	74.1	(2,2,2)
31.31	2.8573	54.8	(2,2,0)
32.00	2.7970	7.7	(2,0,2)
32.87	2.7252	4.5	(0,2,2)
34.65	2.5888	2.9	(0,2,-1)
34.65	2.5888	8.7	(3,2,2)
35.27	2.5446	44.9	(1,2,-1)
35.47	2.5307	21.5	(2,3,1)
35.47	2.5307	21.5	(2,1,-1)
35.74	2.5122	29.2	(1,-1,2)
35.74	2.5122	29.2	(3,1,2)
36.09	2.4884	47.7	(2,-1,1)

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Energy Properties

Formation Energy/atom

-0.56267

eV/atom

Energy/atom

-15.40168

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-15.4017

eV/atom

Volume/atom

12.45

Å³

c/a Ratio

0.9767

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0090

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000030

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Ni · 0.607

Element Family

3d-TM

Solute Fraction

0.393

Interstitial Fraction

0.286

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.9684

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

8.0513

J/mol·K

Ω Parameter

0.4476

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

15.234%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.2138

smaller = more stable mixing

VEC

7.429

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-30.242

kJ/mol; negative = exothermic mixing

Entropy Norm

0.6986

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfjcw

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3292870

Reference Citation

The crystal structure and related material properties of Ac2BeSi8Ni17 were obtained from the Materials Project database (MP-ID: mp-3292870, 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_Ac2BeSi8Ni17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.99686382
_cell_length_b   7.89710690
_cell_length_c   7.81017971
_cell_angle_alpha   61.20724721
_cell_angle_beta   59.93242989
_cell_angle_gamma   58.86031606
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ac2BeSi8Ni17
_chemical_formula_sum   'Ac2 Be1 Si8 Ni17'
_cell_volume   348.47166846
_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
  Ac  Ac0  1  0.25000000  0.25000000  0.25000000  1.0
  Ac  Ac1  1  0.75000000  0.75000000  0.75000000  1.0
  Be  Be2  1  0.00000000  0.00000000  0.00000000  1.0
  Si  Si3  1  0.71135050  0.05728165  0.94271835  1.0
  Si  Si4  1  0.05728165  0.71135050  0.28864950  1.0
  Si  Si5  1  0.21009122  0.55889647  0.78990878  1.0
  Si  Si6  1  0.55889647  0.21009122  0.44110353  1.0
  Si  Si7  1  0.28864950  0.94271835  0.05728165  1.0
  Si  Si8  1  0.94271835  0.28864950  0.71135050  1.0
  Si  Si9  1  0.78990878  0.44110353  0.21009122  1.0
  Si  Si10  1  0.44110353  0.78990878  0.55889647  1.0
  Ni  Ni11  1  0.71872517  0.28127483  0.06081411  1.0
  Ni  Ni12  1  0.28127483  0.71872517  0.93918589  1.0
  Ni  Ni13  1  0.20536491  0.79463509  0.43533383  1.0
  Ni  Ni14  1  0.79463509  0.20536491  0.56466617  1.0
  Ni  Ni15  1  0.43533383  0.56466617  0.20536491  1.0
  Ni  Ni16  1  0.56466617  0.43533383  0.79463509  1.0
  Ni  Ni17  1  0.06081411  0.93918589  0.71872517  1.0
  Ni  Ni18  1  0.93918589  0.06081411  0.28127483  1.0
  Ni  Ni19  1  0.44413246  0.18967921  0.81032079  1.0
  Ni  Ni20  1  0.18967921  0.44413246  0.55586754  1.0
  Ni  Ni21  1  0.93884282  0.69533149  0.06115718  1.0
  Ni  Ni22  1  0.69533149  0.93884282  0.30466851  1.0
  Ni  Ni23  1  0.55586754  0.81032079  0.18967921  1.0
  Ni  Ni24  1  0.81032079  0.55586754  0.44413246  1.0
  Ni  Ni25  1  0.06115718  0.30466851  0.93884282  1.0
  Ni  Ni26  1  0.30466851  0.06115718  0.69533149  1.0
  Ni  Ni27  1  0.50000000  0.50000000  0.50000000  1.0

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