[Ge]
lattice_constant=5.658 Angstrom
Eg0_Gamma=0.89 eV
alpha_Gamma=0.582 meV K-1
beta_Gamma=296 K
Eg0_L=0.742 eV
alpha_L=0.48 meV K-1
beta_L=235 K
spin_orbit_splitting=0.29 eV
eff_mass_DOS_L=0.22 
eff_mass_DOS_X=0.22 
gamma1=13.35
gamma2=4.25
gamma3=5.69 
eff_mass_split_off=0.084
eff_mass_electron=0.12
eff_mass_hh_z=0.33
eff_mass_lh_z=0.043
interband_matrix_element=26.3 eV
c11=126 GPa
c12=44 GPa
c44=67.7 GPa
relative_dielectric_constant=16.2
electron_affinity=4.0 eV
electron_auger_recombination=1e-42
hole_auger_recombination=1e-42
radiative_recombination=6.4e-20

[Si]
lattice_constant=5.431 Angstrom
Eg0_Gamma=4.34 eV
alpha_Gamma=0.391 meV K-1
beta_Gamma=125 K
Eg0_X=1.17 eV
alpha_X=0.473 meV K-1
beta_X=636 K
spin_orbit_splitting=0.044 eV
eff_mass_DOS_L=0.36
eff_mass_DOS_X=0.36
interband_matrix_element=21.6 eV
gamma1=4.22
gamma2=0.39
gamma3=1.44
eff_mass_split_off=0.24
eff_mass_electron=0.26
eff_mass_hh_z=0.49
eff_mass_lh_z=0.16
c11=166 GPa
c12=64 GPa
c44=79.6 GPa
relative_dielectric_constant=11.7
electron_affinity=4.05 eV
electron_auger_recombination=1.1e-42
hole_auger_recombination=3e-43
radiative_recombination=1.1e-20