Si

Elasticity Data ELA

MP-ID: mp-999200 · Space group: I4/mmm (#139)

Materials Project API

Basic Information

Formula

MP-ID

mp-999200

Elements

Sites

Density

2.1938

g/cm³

Volume

85.04

Å³

Cell a

3.8448

Cell b

5.0806

Cell c

5.0806

α Angle

81.77

β Angle

67.77

γ Angle

67.77

Space Group

I4/mmm

Point Group

4/mmm

Crystal System

Tetragonal

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
18.87	4.7029	22.9	(0,1,0)
26.78	3.3286	24.0	(1,0,0)
26.78	3.3286	71.9	(1,1,0)
26.81	3.3254	100.0	(0,1,1)
38.26	2.3526	13.4	(1,0,-1)
38.26	2.3526	13.4	(1,2,0)
38.28	2.3514	14.0	(0,2,0)
43.01	2.1032	22.8	(0,2,1)
47.28	1.9224	24.1	(2,1,1)
47.33	1.9206	68.3	(1,-1,-1)
47.33	1.9206	22.8	(1,2,2)
51.35	1.7795	2.6	(2,1,0)
55.19	1.6643	5.9	(2,0,0)
55.19	1.6643	11.8	(2,2,0)
55.19	1.6643	5.9	(2,2,2)
55.23	1.6631	22.3	(1,0,-2)
55.23	1.6631	22.3	(1,3,0)
55.25	1.6627	1.4	(0,2,2)
58.91	1.5676	22.2	(0,3,0)
62.39	1.4883	3.2	(2,1,-1)
62.39	1.4883	3.2	(2,3,1)
65.82	1.4190	6.3	(2,0,-1)
65.82	1.4190	3.2	(2,3,0)
65.82	1.4190	3.2	(2,3,2)

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Energy Properties

Formation Energy/atom

0.11663

eV/atom

Energy/atom

-8.65713

eV/atom

Energy above Hull

0.1166

eV/atom

Uncorrected Energy

-8.6571

eV/atom

Volume/atom

21.26

Å³

c/a Ratio

1.3214

Electronic Properties

Metallic

Non-metal

Band Gap

0.261

Direct Gap

CBM

N/A

Magnetic Properties

Magnetic

Yes

Total Mag. Moment

0.0000

μB

Mag. Ordering

Unknown

Mag. Sites

Magnetization/Volume

0.000000

μB/Å³

Elastic Properties

K_VRH

81.337

GPa

G_VRH

46.823

GPa

Young's Modulus E

117.854

GPa

Poisson Ratio ν

0.259

Pugh Ratio K/G

1.737

Vickers Hardness Est.

6.946

GPa

Ductility

Ductile

Anisotropy

0.294

Lame λ

50.122

GPa

Feature Analysis

Composition Overview

Element Composition (atomic fraction)

Composition Info

Major / Matrix Element

Si · 1.000

Element Family

Metalloid-Nonmetal

Solute Fraction

0.000

Interstitial Fraction

1.000

Elasticity Features

Elastic Modulus Comparison (GPa)

Elastic Features

Elastic Anisotropy A^U

0.2940

Homogeneous Poisson ν

0.2590

Debye Temperature

551.6

Sound Velocity

5,134.1

m/s

Homogeneity

0.2590

Related Tasks

Related computation task IDs (5)

aaacipyw aaadwkhk aaaelact aaaeolez aaafjdey

Citation & References

Materials Project Page

https://materialsproject.org/materials/mp-999200

Reference Citation

The crystal structure and related material properties of Si were obtained from the Materials Project database (MP-ID: mp-999200, 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   3.84477132
_cell_length_b   5.08062223
_cell_length_c   5.08062223
_cell_angle_alpha   81.76877790
_cell_angle_beta   67.76688585
_cell_angle_gamma   67.76688585
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si
_chemical_formula_sum   Si4
_cell_volume   85.03542034
_cell_formula_units_Z   4
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  0.17880106  0.64239788  0.00000000  1.0
  Si  Si1  1  0.82119894  0.35760212  -0.00000000  1.0
  Si  Si2  1  0.82119894  -0.00000000  0.35760212  1.0
  Si  Si3  1  0.17880106  -0.00000000  0.64239788  1.0

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