RbMg6Nb

High-Entropy Materials HEA Traditional Materials TRA

MP-ID: mp-1017199 · Space group: Amm2 (#38)

Materials Project API

Basic Information

Formula

RbMg6Nb

MP-ID

mp-1017199

Elements

Sites

Density

2.7471

g/cm³

Volume

195.97

Å³

Cell a

6.5794

Cell b

6.5794

Cell c

5.1586

α Angle

90.00

β Angle

90.00

γ Angle

118.65

Space Group

Amm2

Point Group

mm2

Crystal System

Orthorhombic

Bravais Lattice

Stability

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
15.35	5.7739	22.4	(1,0,-1,0)
15.66	5.6588	10.7	(1,-1,0,0)
23.12	3.8469	45.0	(1,0,-1,1)
23.33	3.8123	21.5	(1,-1,0,1)
26.56	3.3567	11.4	(1,1,-2,0)
27.11	3.2888	21.3	(2,-1,-1,0)
30.98	2.8870	20.3	(2,0,-2,0)
31.62	2.8294	14.5	(2,-2,0,0)
34.78	2.5793	35.0	(0,0,0,2)
35.64	2.5193	100.0	(2,0,-2,1)
36.21	2.4808	41.2	(2,-2,0,1)
38.22	2.3550	4.6	(1,0,-1,2)
38.35	2.3470	2.3	(1,-1,0,2)
41.12	2.1953	1.5	(2,1,-3,0)
41.75	2.1634	1.4	(3,-1,-2,0)
42.13	2.1449	1.4	(3,-2,-1,0)
44.29	2.0452	5.6	(1,1,-2,2)
44.65	2.0296	10.7	(2,-1,-1,2)
44.87	2.0200	8.7	(2,1,-3,1)
45.46	1.9950	8.3	(3,-1,-2,1)
45.82	1.9805	8.6	(3,-2,-1,1)
47.23	1.9246	5.0	(3,0,-3,0)
47.26	1.9235	12.1	(2,0,-2,2)
47.71	1.9061	8.9	(2,-2,0,2)

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Energy Properties

Formation Energy/atom

0.39846

eV/atom

Energy/atom

-2.20962

eV/atom

Energy above Hull

0.3985

eV/atom

Uncorrected Energy

-2.2096

eV/atom

Volume/atom

24.50

Å³

c/a Ratio

0.7841

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

0.4128

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.002110

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Mg · 0.750

Element Family

Alkali-AlkEarth

Solute Fraction

0.250

Interstitial Fraction

0.000

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

0.7356

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

6.1160

J/mol·K

Ω Parameter

4.7048

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

15.436%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.1998

smaller = more stable mixing

VEC

2.250

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-1.398

kJ/mol; negative = exothermic mixing

Entropy Norm

0.6696

SS Former

Phase Tendency

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.589

Family

Mg-based Alloy

Matrix Element

Mg · 0.750

Related Tasks

Related computation task IDs (1)

aaadxojm

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-1017199

Reference Citation

The crystal structure and related material properties of RbMg6Nb were obtained from the Materials Project database (MP-ID: mp-1017199, 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_RbMg6Nb
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.57943637
_cell_length_b   6.57943637
_cell_length_c   5.15858600
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   118.64926779
_symmetry_Int_Tables_number   1
_chemical_formula_structural   RbMg6Nb
_chemical_formula_sum   'Rb1 Mg6 Nb1'
_cell_volume   195.97033553
_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
  Rb  Rb0  1  0.91312600  0.08687400  0.00000000  1.0
  Mg  Mg1  1  0.88140700  0.57165500  0.00000000  1.0
  Mg  Mg2  1  0.42834500  0.11859300  0.00000000  1.0
  Mg  Mg3  1  0.42551100  0.57448900  0.00000000  1.0
  Mg  Mg4  1  0.56721900  0.89682600  0.50000000  1.0
  Mg  Mg5  1  0.10317400  0.43278100  0.50000000  1.0
  Mg  Mg6  1  0.09854100  0.90145900  0.50000000  1.0
  Nb  Nb7  1  0.58267700  0.41732300  0.50000000  1.0

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