Ho2NpFe2Si7

High-Entropy Materials HEA

MP-ID: mp-3250388 · Space group: Cmmm (#65)

Materials Project API

Basic Information

Formula

Ho2NpFe2Si7

MP-ID

mp-3250388

Elements

Sites

Density

7.4441

g/cm³

Volume

195.22

Å³

Cell a

12.4671

Cell b

12.4671

Cell c

3.9933

α Angle

90.00

β Angle

90.00

γ Angle

161.67

Space Group

Cmmm

Point Group

mmm

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
7.18	12.3079	3.2	(1,-1,0)
14.39	6.1540	3.7	(2,-2,0)
21.66	4.1026	37.5	(3,-3,0)
22.68	3.9212	11.8	(1,0,0)
23.42	3.7984	52.5	(1,-1,1)
24.91	3.5751	52.9	(2,-1,0)
26.61	3.3499	7.2	(2,-2,1)
28.88	3.0913	3.1	(3,-2,0)
31.99	2.7979	56.1	(1,0,1)
33.65	2.6636	8.4	(2,-1,1)
34.05	2.6329	7.9	(3,-4,0)
34.05	2.6329	7.9	(4,-3,0)
36.50	2.4616	16.8	(5,-5,0)
36.77	2.4445	100.0	(3,-2,1)
36.88	2.4374	53.3	(4,-4,1)
40.03	2.2527	27.0	(5,-4,0)
41.06	2.1981	18.6	(4,-3,1)
44.15	2.0513	3.8	(6,-6,0)
45.42	1.9967	27.1	(0,0,2)
45.68	1.9860	26.7	(1,1,0)
46.27	1.9620	3.9	(5,-4,1)
46.58	1.9497	2.3	(5,-6,0)
46.58	1.9497	2.3	(6,-5,0)
50.86	1.7953	8.4	(3,-3,2)

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Energy Properties

Formation Energy/atom

-0.50634

eV/atom

Energy/atom

-20.42551

eV/atom

Energy above Hull

0.0432

eV/atom

Uncorrected Energy

-20.4255

eV/atom

Volume/atom

16.27

Å³

c/a Ratio

0.3203

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

0.1200

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000610

μB/Å³

Elastic Properties

Elastic data not available

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Si · 0.583

Element Family

Metalloid-Nonmetal

Solute Fraction

0.417

Interstitial Fraction

0.583

High-Entropy Alloy Features

Composite Radar (normalized)

Element-Class Share

Mix Entropy ΔS/R

1.1187

HEA criterion (>1.0 = high entropy)

Mix Entropy ΔS

9.3012

J/mol·K

Ω Parameter

1.1281

Ω > 1.1 favors solid solution

Atomic Size Mismatch δr

18.394%

δr < 6.6% favors single-phase solid solution

Electronegativity Diff Δχ

0.2676

smaller = more stable mixing

VEC

6.000

valence electron concentration, affects phase stability

Mix Enthalpy ΔH_mix

-13.611

kJ/mol; negative = exothermic mixing

Entropy Norm

0.8070

SS Former

Phase Tendency

Related Tasks

Related computation task IDs (1)

aaahcygy

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-3250388

Reference Citation

The crystal structure and related material properties of Ho2NpFe2Si7 were obtained from the Materials Project database (MP-ID: mp-3250388, 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_Ho2NpFe2Si7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.46711868
_cell_length_b   12.46711897
_cell_length_c   3.99334306
_cell_angle_alpha   90.00000000
_cell_angle_beta   90.00000000
_cell_angle_gamma   161.66801919
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ho2NpFe2Si7
_chemical_formula_sum   'Ho2 Np1 Fe2 Si7'
_cell_volume   195.21821089
_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  0.09937323  0.90062677  0.50000000  1.0
  Ho  Ho1  1  0.46675311  0.53324689  0.50000000  1.0
  Np  Np2  1  0.78307183  0.21692817  0.00000000  1.0
  Fe  Fe3  1  0.65484049  0.34515951  0.00000000  1.0
  Fe  Fe4  1  0.91127255  0.08872745  0.00000000  1.0
  Si  Si5  1  0.37082518  0.62917482  0.00000000  1.0
  Si  Si6  1  0.56293759  0.43706241  0.00000000  1.0
  Si  Si7  1  0.87074995  0.12925005  0.50000000  1.0
  Si  Si8  1  0.00321867  0.99678133  0.00000000  1.0
  Si  Si9  1  0.19528049  0.80471951  0.00000000  1.0
  Si  Si10  1  0.28301750  0.71698250  0.50000000  1.0
  Si  Si11  1  0.69536043  0.30463957  0.50000000  1.0

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