Supporting Information Silicon Framework-based Lithium Silicides at ...

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Supporting Information

Silicon Framework-based Lithium Silicides at High Pressures Shoutao Zhang1, Yanchao Wang1, Guochun Yang1,2,* and Yanming Ma1,*

1

State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, China 2   Centre for Advanced Optoelectronic Functional Materials Research and Key Laboratory for UV Light-Emitting Materials and Technology of Ministry of Education, Northeast Normal University, Changchun 130024, China,

*

 

E-mail: [email protected] and [email protected]

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Supporting Figures

Figure S1. Comparison of the fitted Birch-Murnaghan equation of states for LiSi in the Pm-3m structure by using the calculated results from the PAW pseudopotentials and the full-potential LAPW methods.

 

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Figure S2. Chemical stabilities of Li-Si system at ambient pressure. The formation enthalpies of Li-Si compounds are relative to the enthalpies of elemental decomposition into solidified phases of Li and Si. Dashed lines connect data points, and solid lines denote the convex hull. Fm-3m structure of elemental Li and Fd-3m structure of elemental Si were adopted to calculate the formation enthalpies. Several structures (e.g. Li3Si2, Li2Si, Li3Si, and Li4Si) predicted by minima hopping method are also included and denoted by blue triangles. The formation enthalpies of our predicted structures (e.g. Li3Si2, Li2Si, Li3Si) are equal to those of structures obtained by minima hopping method. In other words, structures predicted by minima hopping method are well reproduced by our calculations. For Li4Si composition, the formation enthalpy of our predicted P213 structure (4 formula units) is slightly lower than that of I4/m (2 formula units). This might originate from the smaller unit cells used in minima hopping simulations (i.e. Unit cell contains maximum number of 16 atoms in their simulations).

 

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Figure S3. Phonon spectra of LiSi4 with Cmmm symmetry at 25 GPa.

Figure S4. Phonon spectra of LiSi3 with P6/mmm symmetry at 25 GPa.

 

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Figure S5. Phonon spectra of LiSi2 with P2/m symmetry at 25 GPa.

Figure S6. Phonon spectra of Li2Si3 with P2/m symmetry at 25 GPa.

 

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Figure S7. Phonon spectra of LiSi with P4/mmm symmetry at 25 GPa.

Figure S8. Phonon spectra of Li2Si with P6/mmm symmetry at 25 GPa.

 

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Figure S9. Phonon spectra of Li3Si with Fm-3m symmetry at 25 GPa.

Figure S10. Phonon spectra of Li4Si with R-3m symmetry at 25 GPa.

 

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Figure S11. Electronic band structure and projected density of states of LiSi4 with Cmmm symmetry at 25 GPa.

Figure S12. Electronic band structure and projected density of states of LiSi3 with P6/mmm symmetry at 25 GPa.

Figure S13. Electronic band structure and projected density of states of LiSi2 with P2/m symmetry at 25 GPa.

 

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Figure S14. Electronic band structure and projected density of states of Li2Si3 with P2/m symmetry at 25 GPa.

Figure S15. Electronic band structure and projected density of states of LiSi with P4/mmm symmetry at 25 GPa.

Figure S16. Electronic band structure and projected density of states of Li2Si with P6/mmm symmetry at 25 GPa.

 

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Figure S17. Electronic band structure and projected density of states of Li3Si with Fm-3m symmetry at 25 GPa.

Figure S18. Electronic band structure and projected density of states of Li4Si with R-3m symmetry at 25 GPa.

Figure S19. Calculated ELF in the (100) plane for LiSi4 with Cmmm symmetry.

 

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Table S1. Detailed structural information of the predicted stable Li-Si compounds at selected pressures. Phases P Lattice Atomic coordinates (GPa) Parameters (fractional) Atoms x y z (Å,  °) LiSi4-Cmmm 25 Li(2a) 0.0000 0.0000 0.0000 a = 4.2071 b = 12.0560

Si(4j)

0.5000 0.0966 0.5000

c = 2.3850

Si(4j)

1.0000 0.1954 0.5000

a = b = 5.1492

Li(2a)

0.0000 0.0000 0.0000

c = 3.2859

Si(8h)

0.7050 0.1029 0.0000

a = b = 4.7810

Li(1b)

0.0000 0.0000 0.5000

c = 2.4231

Si(3g)

0.5000 0.0000 0.0000

a = b = 3.4120

Li(1c)

0.5000 0.5000 0.0000

c = 10.7123

Li(2g)

0.0000 0.0000 0.3353

α = β = γ = 90.0000

Si(1a)

0.0000 0.0000 0.0000

Si(4i)

0.5000 0.0000 0.1670

Si(2h)

0.5000 0.5000 0.3342

Si(2e)

0.5000 0.0000 0.5000

a = b = 3.2140

Li(2b)

0.5000 0.5000 0.0000

c = 6.6560

Si(2a)

0.0000 0.0000 0.0000

α = β = γ = 90.0000

Si(4d)

0.5000 0.0000 0.2500

a = 6.1002

Li(2m)

0.3141 0.0000 0.6878

b = 2.4435

Si(1b)

0.0000 0.5000 0.0000

c = 4.6895

Si(1f)

0.0000 0.5000 0.5000

α = γ = 90.0000

Si(2n)

0.3518 0.5000 0.1958

a = 8.0690

Li(2n)

0.1038 0.5000 0.2859

b = 2.4322

Li(2n)

0.3087 0.5000 0.8673

c = 6.1309

Si(1a)

1.0000 0.0000 0.0000

α = γ = 90.0000

Si(2m)

0.1818 0.0000 0.5920

α = β = γ = 90.0000 LiSi4-I4/m

100

α = β = γ = 90.0000 LiSi3-P6/mmm 25

α = β = 90.0000 γ = 120.0000 LiSi3-P4/mmm 40

LiSi3-I4/mmm

LiSi2-P2/m

100

25

β = 82.4464 Li2Si3-P2/m

 

25

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Si(2m)

0.3856 0.0000 0.1858

Si(1g)

0.5000 0.0000 0.5000

a = b = 2.4107

Li(1a)

0.0000 0.0000 0.0000

c = 3.7057

Si(1d)

0.5000 0.5000 0.5000

a = b = c = 2.4878

Li(1a)

0.0000 0.0000 0.0000

α = β = γ = 90.0000

Si(1b)

0.5000 0.5000 0.5000

a = b = 3.8592

Li(2d)

0.6666 0.3333 0.5000

c = 2.3779

Si(1a)

0.0000 0.0000 0.0000

a = b = 2.4180

Li(4e)

0.5000 0.5000 0.1798

c = 7.2867

Si(2a)

0.0000 0.0000 0.0000

a = b = c = 5.4488

Li(4a)

0.0000 0.0000 0.0000

α = β = γ = 90.0000

Li(8c)

0.7500 0.7500 0.7500

Si(4b)

0.0000 0.0000 0.5000

β = 68.7800 LiSi-P4/mmm

25

α = β = γ = 90.0000 LiSi-Pm-3m

100

Li2Si-P6/mmm 25

α = β = 90.0000 γ = 120.0000 Li2Si-I4/mmm

100

α = β = γ = 90.0000 Li3Si-Fm-3m

Li3Si-Fmmm

25

100

a = 3.5431

Li(16m) 0.5000 0.8134 0.6510

b = 10.1694

Li(8i)

0.5000 0.0000 0.3343

c = 6.1197

Si(8h)

0.5000 0.8913 0.0000

a = b = 3.9295

Li(6c)

0.0000 0.0000 0.7891

c = 11.3365

Li(6c)

0.0000 0.0000 0.6009

α = β = 90.0000

Si(3a)

0.0000 0.0000 1.0000

a = b = 4.7398

Li(8h)

0.2928 0.0437 0.0000

c = 3.8116

Si(2b)

0.0000 0.0000 0.5000

a = 3.5597

Li(32h)

0.0308 0.6753 0.9261

b = 6.2592

Si(8a)

0.2500 0.7500 0.2500

α = β = γ = 90.0000 Li4Si-R-3m

25

γ = 120.0000 Li4Si-I4/m

45

α = β = γ = 90.0000 Li4Si-Fddd

100

c = 11.9973 α = β = γ = 90.0000

 

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