Energy gap  1.424 eV 
Energy separation (E_{ΓL}) between Γ and L valleys  0.29 eV 
Energy separation (E_{ΓX}) between Γ and X valleys  0.48 eV 
Energy spinorbital splitting  0.34 eV 
Intrinsic carrier concentration  2.1·10^{6} cm^{3} 
Intrinsic resistivity  3.3·10^{8} Ω·cm 
Effective conduction band density of states  4.7·10^{17} cm^{3} 
Effective valence band density of states  9.0·10^{18} cm^{3} 
Band structure and carrier concentration of GaAs. 300 K E_{g} = 1.42 eV E_{L} = 1.71 eV E_{X}= 1.90 eV E_{so} = 0.34 eV 
E_{g}=1.5195.405·10^{4}·T^{2}/(T+204) (eV)
where T is temperatures in degrees K (0 < T < 10^{3}).
Temperature dependence of the energy difference between the top of the valence band and the bottom of the Lvalley of the conduction band
E_{L}=1.8156.05·10^{4}·T^{2}/(T+204) (eV)
Temperature dependence of the energy difference between the top of the valence band and the bottom of the Xvalley of the conduction band
E_{L}=1.9814.60·10^{4}·T^{2}/(T+204) (eV)
The temperature dependences of the relative populations of the Γ, L and X valleys. (Blakemore [1982]). 

The temperature dependences of the intrinsic carrier concentration. (Shur [1990]). 
n_{i} =(N_{c} ·N_{ν} )^{1/2}exp(E_{g}/(2k_{b}T))
Effective density of states in the conduction band taking into account the nonparabolicity of the Γvalley and contributions from the X and Lvalleys
N_{c}= 8.63·10^{13}·T^{3/2}[11.9310^{4}·T4.19·10^{8}·T^{2} +21·exp(E_{ΓL}/(2k_{b}T))
+44·exp(E_{ΓX}/(2k_{b}T)) (cm^{3})
N_{v}= 1.83·10^{15}·T^{3/2}(cm^{3})
Fermi level versus temperature for different concentrations of shallow donors and acceptors. 
Energy gap narrowing at high doping levels. (Tiwari and Wright [1990]) 
ΔEg ≈ 2_{}·10^{11}·N_{a}^{1/2} (eV) (N_{a} in cm.^{3})
For Γvalley  m_{Γ} = 0.063m_{o} 
In the Lvalley the surfaces of equal energy are ellipsoids  
m_{l}= 1.9m_{o}  
m_{t}= 0.075m_{o}  
Effective mass of density of states  
m_{L}=(16m_{l}m_{t}^{2})^{1/3}  m_{L}=0.85m_{o} 
In the Xvalley the surfaces of equal energy are ellipsoids  
m_{l}= 1.9m_{o}  
m_{t}= 0.19m_{o}  
Effective mass of density of states  
m_{X}=(9m_{l}m_{t}^{2})^{1/3}  m_{X}=0.85m_{o} 
Heavy  m_{h} = 0.51m_{o} 
Light  m_{lp} = 0.082m_{o} 
Splitoff band  m_{so} = 0.15m_{o} 
Effective mass of density of states  m_{v} = 0.53m_{o} 
S  Se  Si  Ge  Sn  Te 
~0.006  ~0.006  ~0.006  ~0.006  ~0.006  ~0.03 
C  Si  Ge  Zn  Sn 
~0.02  ~0.03/0.1/0.22  ~0.03  ~0.025  ~0.2 