Li4Ac4Si5Pb

High-Entropy Materials HEA

MP-ID: mp-3252432 · Space group: Amm2 (#38)

Materials Project API

Basic Information

Formula

Li4Ac4Si5Pb

MP-ID

mp-3252432

Elements

Sites

Density

6.4130

g/cm³

Volume

332.31

Å³

Cell a

10.0826

Cell b

10.0826

Cell c

7.1176

α Angle

90.00

β Angle

90.00

γ Angle

152.66

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
9.03	9.7970	1.9	(1,-1,0)
12.44	7.1176	5.7	(0,0,1)
15.39	5.7584	7.1	(1,-1,1)
18.11	4.8985	1.8	(2,-2,0)
19.17	4.6306	55.8	(1,0,0)
22.03	4.0352	30.5	(2,-2,1)
23.10	3.8498	14.7	(2,-1,0)
25.02	3.5588	43.9	(0,0,2)
26.32	3.3862	3.6	(2,-1,1)
27.31	3.2657	2.0	(3,-3,0)
29.51	3.0269	5.3	(3,-2,0)
30.11	2.9682	28.5	(3,-3,1)
31.71	2.8217	28.3	(1,0,2)
31.71	2.8217	28.3	(0,1,2)
32.13	2.7854	100.0	(3,-2,1)
34.32	2.6133	8.2	(2,-1,2)
36.69	2.4492	4.2	(4,-4,0)
37.37	2.4061	2.4	(3,-3,2)
37.75	2.3828	22.3	(1,1,0)
38.89	2.3160	5.1	(4,-4,1)
39.07	2.3057	5.2	(3,-2,2)
39.42	2.2858	1.0	(4,-3,1)
40.99	2.2018	1.3	(2,0,1)
42.33	2.1353	10.7	(2,-2,3)

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Energy Properties

Formation Energy/atom

-0.63639

eV/atom

Energy/atom

-28.08287

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-28.0829

eV/atom

Volume/atom

23.74

Å³

c/a Ratio

0.7059

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 · 0.357

Element Family

Metalloid-Nonmetal

Solute Fraction

0.643

Interstitial Fraction

0.357

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.2721

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

10.5762

J/mol·K

Ω Parameter

1.1444

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

20.627%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.4750

smaller = more stable mixing

VEC

2.571

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-10.656

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9176

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahdbho

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3252432

Reference Citation

The crystal structure and related material properties of Li4Ac4Si5Pb were obtained from the Materials Project database (MP-ID: mp-3252432, 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_Li4Ac4Si5Pb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.08258510
_cell_length_b   10.08258466
_cell_length_c   7.11762048
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   152.66003795
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Li4Ac4Si5Pb
_chemical_formula_sum   'Li4 Ac4 Si5 Pb1'
_cell_volume   332.31194081
_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
  Li  Li0  1  0.81575531  0.18424469  0.56848833  1.0
  Li  Li1  1  0.18595381  0.81404619  0.44722784  1.0
  Li  Li2  1  0.18595381  0.81404619  0.05277216  1.0
  Li  Li3  1  0.81575531  0.18424469  0.93151167  1.0
  Ac  Ac4  1  0.54762197  0.45237803  0.25000000  1.0
  Ac  Ac5  1  0.44764419  0.55235581  0.75000000  1.0
  Ac  Ac6  1  0.34415684  0.65584316  0.25000000  1.0
  Ac  Ac7  1  0.65878702  0.34121298  0.75000000  1.0
  Si  Si8  1  0.94469749  0.05530251  0.07842214  1.0
  Si  Si9  1  0.05468047  0.94531953  0.92012584  1.0
  Si  Si10  1  0.05468047  0.94531953  0.57987416  1.0
  Si  Si11  1  0.94469749  0.05530251  0.42157786  1.0
  Si  Si12  1  0.28087029  0.71912971  0.75000000  1.0
  Pb  Pb13  1  0.71874654  0.28125346  0.25000000  1.0

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