The metallization and superconductivity of
dense hydrogen sulfide
Supplementary Material
Yinwei Li1*, Jian Hao1, Hanyu Liu2, Yanling Li1, and Yanming
Ma2†
1
School of Physics and Electronic Engineering, Jiangsu Normal University, Xuzhou
221116, P. R. China
2
Department of Physics and Engineering Physics, University of Saskatchewan, Saskat
chewan, Canada, S7N 5E2
3
State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, P. R.
China
Correspondence and requests for materials should be addressed to Y. L. and Y. Ma
(yinwei_li@jsnu.edu.cn, mym@jlu.edu.cn).
The supplementary material contains:

The structural parameters of the predicted structures (Tab. SI1)

Valence electron localization functions (ELF) of the predicted structures (Fig.
SI1)

The Phonon dispersion curves of the predicted structures (Fig. SI2)

Band structures of the predicted structures (Fig. SI3)
TABLE SI1. Calculated structural parameters of the predicted stable structures for
H2S at selected pressures.
Space group
Pressure (GPa)
Lattice parameters (Å)
Atomic coordinates (fractional)
P2/c
15
a = 5.6255
b = 3.4427
c = 6.9633
β =127.44°
S (2e)
S (2f)
H1 (4a)
H2 (4a)
(0, 0.618, 0.25)
(0.5, 0.996, 0.25)
(0.155, 0.346, 0.225)
(0.345, 0.273, 0.573)
Pc
30
a = 5.0942
b = 3.1959
c = 5.3287
β =89.62°
Pmc21
70
a = 4.6806
b = 2.9349
c = 4.9479
S1 (2a)
S2 (2a)
H1 (2a)
H2 (2a)
H3 (2a)
H4 (2a)
S1 (2a)
S2 (2b)
H1 (2b)
H2 (2a)
H3 (4c)
(0.999, 0.192, 0.640)
(0.494, 0.351, 0.342)
(0.498, 0.062, 0.528)
(0.977, 0.426, 0.857)
(0.777, 0.052, 0.201)
(0.271, 0.849, 0.739)
(0, 0.179, 0.623)
(0.5, 0.375, 0.355)
(0.5, 0.048, 0.545)
(0, 0.445, 0.858)
(0.751, 0.119, 0.213)
P-1
90
S1 (2i)
H1 (2i)
H2 (1g)
H3 (1f)
(0.308, 0.183, 0.245)
(0.241, 0.415, 0.837)
(0.000, 0.500, 0.500)
(0.500, 0.000, 0.500)
Cmca
170
a = 2.7804
b = 2.7926
c = 4.2568
α = 101.72°
β = 76.53°
γ = 109.58°
a = 2.9986
b = 4.3274
c = 7.6005
S1 (8f) (0.000, 0.371, 0.615)
H1 (8f) (0.000, 0.372, 0.270)
H2 (8f) (0.000, 0.600, 0.092)
Fig. SI1. Valence electron localization function (ELF) in the planes containing S-H
bonds of the P2/c structure at 15 GPa, (b) the Pc structure at 30 GPa and (c) the
Pmc21 structure at 70 GPa. ELF[1] is a local electrons pair probability for
identification of localized electronic groups, and a dimensionless, empirical function
in 3-space that generates relatively large values ranging between 0.5 and 1.0 in
regions that can be ascribed to bonding and nonbonding localized electrons and
smaller values (less than 0.5) where one expects the electrons to be delocalized.
Fig. SI2. The calculated phonon dispersions of H2S for experimental Phase III
(Pbcm) at ambient pressure (a), the predicted P2/c at 15 GPa (b), Pc at 30 GPa (c) and
Pmc21 at 70 GPa (d). No any imaginary phonons were found to confirm the structural
stabilities of these phases.
Fig. SI3. (a)-(e) show the electronic band structures of H2S for the experimental
Phase III (Pbcm) at ambient pressure, the predicted P2/c at 15 GPa, Pc at 40
GPa, Pmc21 at 70GPa, and P-1 at 120 GPa, respectively. The band gaps in (a e) have been revised by performing HSE06 [2, 3] hybrid functional
calculations as implanted in the VASP code.
References
[1] A. D. Becke, and K. E. Edgecombe, J. Chem. Phys. 92, 5397 (1990).
[2] A. V. Krukau, O. A. Vydrov, A. F. Izmaylov, and G. E. Scuseria, J. Chem. Phys. 125, 224106
(2006).
[3] J. Heyd, G. E. Scuseria, and M. Ernzerhof, J. Chem. Phys. 118, 8207 (2003).