Tb7Er3(PPb3)2

High-Entropy Materials HEA

MP-ID: mp-3296767 · Space group: P312 (#149)

Materials Project API

Basic Information

Formula

Tb7Er3(PPb3)2

MP-ID

mp-3296767

Elements

Sites

Density

9.9033

g/cm³

Volume

489.51

Å³

Cell a

9.0884

Cell b

9.0884

Cell c

6.8432

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
11.24	7.8708	5.5	(1,0,-1,0)
23.50	3.7856	7.5	(2,-1,-1,1)
26.04	3.4216	27.6	(0,0,0,2)
28.44	3.1379	8.7	(1,0,-1,2)
30.04	2.9749	9.2	(3,-1,-2,0)
30.04	2.9749	18.5	(3,-2,-1,0)
32.76	2.7334	100.0	(2,-1,-1,2)
32.83	2.7282	42.9	(3,-1,-2,1)
32.83	2.7282	85.7	(3,-2,-1,1)
34.18	2.6236	15.1	(3,0,-3,0)
34.18	2.6236	30.1	(3,-3,0,0)
34.74	2.5821	15.4	(2,0,-2,2)
39.67	2.2721	1.0	(4,-2,-2,0)
40.17	2.2450	1.6	(3,-1,-2,2)
41.36	2.1830	7.3	(4,-1,-3,0)
41.89	2.1564	7.7	(4,-2,-2,1)
41.89	2.1564	3.9	(2,-4,2,1)
43.52	2.0797	12.5	(4,-1,-3,1)
43.52	2.0797	12.5	(4,-3,-1,1)
44.44	2.0386	1.1	(2,-1,-1,3)
46.13	1.9677	1.5	(4,0,-4,0)
48.07	1.8928	11.9	(4,-2,-2,2)
48.07	1.8928	5.9	(2,-4,2,2)
50.41	1.8102	39.1	(3,-1,-2,3)

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Energy Properties

Formation Energy/atom

-1.00962

eV/atom

Energy/atom

-38.56941

eV/atom

Energy above Hull

0.0000

eV/atom

Uncorrected Energy

-38.5694

eV/atom

Volume/atom

27.20

Å³

c/a Ratio

0.7530

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

Tb · 0.389

Element Family

Lanthanide

Solute Fraction

0.611

Interstitial Fraction

0.111

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.2763

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

10.6108

J/mol·K

Ω Parameter

3.0299

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

12.175%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.5763

smaller = more stable mixing

VEC

7.389

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-4.095

kJ/mol; negative = exothermic mixing

Entropy Norm

0.9206

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahfowt

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3296767

Reference Citation

The crystal structure and related material properties of Tb7Er3(PPb3)2 were obtained from the Materials Project database (MP-ID: mp-3296767, 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_Tb7Er3(PPb3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.08840428
_cell_length_b   9.08840308
_cell_length_c   6.84320152
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   119.99999372
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Tb7Er3(PPb3)2
_chemical_formula_sum   'Tb7 Er3 P2 Pb6'
_cell_volume   489.51410072
_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
  Tb  Tb0  1  0.76253856  0.76270992  0.24961149  1.0
  Tb  Tb1  1  0.23729008  0.99982964  0.24961149  1.0
  Tb  Tb2  1  0.00017036  0.23746144  0.24961149  1.0
  Tb  Tb3  1  0.23729008  0.23746144  0.75038851  1.0
  Tb  Tb4  1  0.76253856  0.99982964  0.75038851  1.0
  Tb  Tb5  1  0.00017036  0.76270992  0.75038851  1.0
  Tb  Tb6  1  0.66666700  0.33333300  0.50000000  1.0
  Er  Er7  1  0.33333300  0.66666700  0.50000000  1.0
  Er  Er8  1  0.33333300  0.66666700  0.00000000  1.0
  Er  Er9  1  0.66666700  0.33333300  0.00000000  1.0
  P  P10  1  0.00000000  0.00000000  0.50000000  1.0
  P  P11  1  0.00000000  0.00000000  0.00000000  1.0
  Pb  Pb12  1  0.40140723  0.40227249  0.24853660  1.0
  Pb  Pb13  1  0.59772751  0.99913475  0.24853660  1.0
  Pb  Pb14  1  0.00086525  0.59859277  0.24853660  1.0
  Pb  Pb15  1  0.59772751  0.59859277  0.75146340  1.0
  Pb  Pb16  1  0.40140723  0.99913475  0.75146340  1.0
  Pb  Pb17  1  0.00086525  0.40227249  0.75146340  1.0

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