CdGeN2

Contents

• Crystal Structures

• Synthesis and Growth

• Electronic Band Structure

• Vibrational properties

• Elastic properties

• Optical and dielectric properties

Crystal Structures

Spacegroup: Pnb2₁

Point group: C_2v

Lattice constants:

Wyckoff positions:

[1]

[2]

Synthesis and growth

not reported yet

Electronic band structure

Band gap direct at Γ.

Band gap:

m_x =2.676 m_y =2.344 m_z =0.713 [2]

Band structure figures can be found in [1].

Figures:

Figure 1:Band structure of CdGeN2. From data published in [2].

Figure 2: Band structure near valence band maximum [2].

Vibrational Properties

Modes at zone center. [3]

Infrared spectra [3].

Derived average elastic constant G=shear elastic constants (in GPa) , B=bulk modulus

Y= Young's modulus R Reuss average over angles of the compliances, V Voigt average

average over angles of the stiffnesses, without subscript average of Reuss and Voigt

𝜈 = Poisson ratio, [4]

Piezoelectric constants ( in C/m²) [4]

Spontaneous polarization -0.023 C/m² [4]

Optical and dielectric properties

high-frequency and static dielectric constants [3]

Index of refraction [3]

Second-order non-linear susceptibility (in pm/V) [5]

using different pseudopotentials HGH Hartwigsen Goedecker, Hutter

FHI Fritz-Haber Institute

both from abinit website

+sc means including scissor's correction of band gap

Pockels coefficients (pm/V) [5]

References

[1]. A. Punya and W. R. L. Lambrecht, Mater. Sci. Forum Vols. 717-720 (2012) pp.1331-1334

[2].Sai Lyu and Walter R. L. Lambrecht Phy. Rev. Mater. 1, 024606 (2017)

[3] Sai Lyu and Walter R. L. Lambrecht, J. Appl. Phys. 123, 205701 (2018)

[4] Sai Lyu and Walter R. L. Lambrecht, J. Appl. Phys. 124, 055705 (2018)

[5] Sai Lyu and Walter R. L. Lambrecht, Phys. Rev. Mater. 2, 124602 (2018)