The Seebeck coefficient derived in the above Onsager formulation is the mixing component α S,mix, which dominates in most semiconductors. The vibrational component in high-band gap materials such as B 13 C 2 is very important. Considering the microscopic transport (transport is a results of nonequilibrium), j e = − − e c ℏ ℏ 3 ∑ ∑ p u e f e ′ ′ = − − e c ℏ ℏ 3 k B T ∑ ∑ p u e τ τ e ( − − ∂ ∂ f e o ∂ ∂ E e ) ( u e ⋅ ⋅ F t e ) , q = 1 ℏ ℏ 3 ∑ ∑ p ( E e − − E F ) u e f e ′ ′ = 1 ℏ ℏ 3 k B T ∑ ∑ p u e τ τ e ( − − ∂ ∂ f e o ∂ ∂ E e ) ( E e − − E F ) ( u e ⋅ ⋅ F t e ) ,