Si

Traditional Materials TRA

MP-ID: mp-644693 · Space group: P1 (#1)

Materials Project API

Basic Information

Formula

MP-ID

mp-644693

Elements

Sites

Density

2.1429

g/cm³

Volume

174.11

Å³

Cell a

5.4551

Cell b

3.9746

Cell c

9.1447

α Angle

78.23

β Angle

108.78

γ Angle

111.24

Space Group

Point Group

Crystal System

Triclinic

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
10.27	8.6152	100.0	(0,0,1)
18.13	4.8931	85.1	(1,0,0)
18.26	4.8597	36.3	(1,0,-1)
20.62	4.3076	96.9	(0,0,2)
23.22	3.8310	3.6	(1,0,1)
23.51	3.7833	33.5	(1,0,-2)
24.14	3.6864	1.9	(0,1,0)
24.25	3.6708	14.0	(1,-1,-1)
25.17	3.5384	37.1	(1,-1,0)
25.32	3.5175	32.9	(0,1,1)
27.24	3.2740	3.2	(0,1,-1)
27.56	3.2360	10.9	(1,-1,-2)
29.97	2.9817	43.5	(1,-1,1)
30.31	2.9488	31.5	(0,1,2)
31.14	2.8717	7.4	(0,0,3)
31.17	2.8694	12.3	(1,0,2)
31.55	2.8360	42.4	(1,0,-3)
33.52	2.6731	16.4	(0,1,-2)
34.84	2.5749	4.4	(1,1,0)
34.88	2.5723	10.7	(2,-1,-1)
35.31	2.5421	1.3	(2,0,-1)
35.65	2.5186	26.0	(1,1,-1)
35.87	2.5037	3.4	(2,-1,-2)
37.00	2.4299	56.6	(2,0,-2)

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Energy Properties

Formation Energy/atom

0.41512

eV/atom

Energy/atom

-8.35865

eV/atom

Energy above Hull

0.4151

eV/atom

Uncorrected Energy

-5.0102

eV/atom

Volume/atom

21.76

Å³

c/a Ratio

1.6763

Electronic Properties

Metallic

Metal

Band Gap

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Total Mag. Moment

0.0011

μB

Mag. Ordering

Mag. Sites

Magnetization/Volume

0.000010

μB/Å³

Elastic Properties

K_VRH

49.084

GPa

G_VRH

20.284

GPa

Young's Modulus E

53.484

GPa

Poisson Ratio ν

0.318

Pugh Ratio K/G

2.420

Vickers Hardness Est.

GPa

Ductility

Brittle

Anisotropy

11.527

Lame λ

35.561

GPa

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Si · 1.000

Element Family

N/A

Solute Fraction

0.000

Interstitial Fraction

1.000

Traditional Material Features

ROM Blended-Feature Radar

Rating & Classification

Tier

Score

0.373

Family

Pure Metal

Matrix Element

Si · 1.000

Related Tasks

Related computation task IDs (1)

aaadxowf

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-644693

Reference Citation

The crystal structure and related material properties of Si were obtained from the Materials Project database (MP-ID: mp-644693, 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_Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.45513625
_cell_length_b   3.97462346
_cell_length_c   9.14468512
_cell_angle_alpha   78.22843373
_cell_angle_beta   108.78166373
_cell_angle_gamma   111.23949886
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si
_chemical_formula_sum   Si8
_cell_volume   174.10767850
_cell_formula_units_Z   8
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
  Si  Si0  1  0.82765500  0.09474000  0.08233300  1.0
  Si  Si1  1  0.21100200  0.00072400  0.05971100  1.0
  Si  Si2  1  0.00363400  0.56659500  0.24071800  1.0
  Si  Si3  1  0.36170500  0.12570700  0.62845900  1.0
  Si  Si4  1  0.06950100  0.84100800  0.80164500  1.0
  Si  Si5  1  0.84225300  0.28671500  0.68233000  1.0
  Si  Si6  1  0.13266900  0.56787400  0.51132200  1.0
  Si  Si7  1  0.56641800  0.50925300  0.00009200  1.0

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