[ − 1 2 ∇ 2 + V ( r ) ] φ i ( r ) + ∑ j ≠ i ∫ | φ j ( r ′ ) | 2 | r − r ′ | φ i ( r ) d r ′ − ∑ j ≠ i , | | ∫ φ j ∗ ( r ′ ) φ i ( r ′ ) | r − r ′ | φ j ( r ) d r ′ = E i φ i ( r ) {\displaystyle \left[-{\frac {1}{2}}\nabla ^{2}+V(\mathbf {r} )\right]\varphi _{i}(\mathbf {r} )+\sum _{j\neq i}\int {\frac {|\varphi _{j}(r')|^{2}}{|r-r'|}}\varphi _{i}(r)dr'-\sum _{j\neq i,||}\int {\frac {\varphi _{j}^{*}(r')\varphi _{i}(r')}{|r-r'|}}\varphi _{j}(r)dr'=E_{i}\varphi _{i}(\mathbf {r} )}
H ^ = − ℏ 2 2 m e ∑ i ∇ r i 2 − ℏ 2 2 M i ∑ i ∇ R i 2 − ∑ i , j Z i e 2 | R i − r j | + 1 2 ∑ i ≠ j e 2 | r i − r j | + 1 2 ∑ i ≠ j e 2 Z i Z j | R i − R j | {\displaystyle {\hat {H}}=-{\frac {\hbar ^{2}}{2{m_{e}}}}\sum _{i}\nabla _{\mathbf {r} _{i}}^{2}-{\frac {\hbar ^{2}}{2{M_{i}}}}\sum _{i}\nabla _{\mathbf {R} _{i}}^{2}-\sum _{i,j}{\frac {Z_{i}e^{2}}{|\mathbf {R} _{i}-\mathbf {r} _{j}|}}+{\frac {1}{2}}\sum _{i\neq j}{\frac {e^{2}}{|\mathbf {r} _{i}-\mathbf {r} _{j}|}}+{\frac {1}{2}}\sum _{i\neq j}{\frac {e^{2}Z_{i}Z_{j}}{|\mathbf {R} _{i}-\mathbf {R} _{j}|}}}
n ( r ) = ∑ σ n ( r , σ ) = ∑ σ ∑ i = 1 N σ | ψ i σ ( r ) | 2 {\displaystyle n(r)=\sum _{\sigma }n(r,\sigma )=\sum _{\sigma }\sum _{i=1}^{N^{\sigma }}|\psi _{i}^{\sigma }(r)|^{2}}
T s = − 1 2 ∑ σ ∑ i = 1 N σ ⟨ ψ i σ | ∇ 2 | ψ i σ ⟩ = 1 2 ∑ σ ∑ i = 1 N σ d 3 r | ∇ ψ i σ ( r ) | 2 {\displaystyle T_{s}=-{\frac {1}{2}}\sum _{\sigma }\sum _{i=1}^{N^{\sigma }}\langle \psi _{i}^{\sigma }|\nabla ^{2}|\psi _{i}^{\sigma }\rangle ={\frac {1}{2}}\sum _{\sigma }\sum _{i=1}^{N^{\sigma }}d^{3}r|\nabla \psi _{i}^{\sigma }(r)|^{2}}
E H a r t r e e = 1 2 ∫ d 3 r d 3 r ′ n ( r ) n ( r ′ ) | r − r ′ | {\displaystyle E_{Hartree}={\frac {1}{2}}\int d^{3}rd^{3}r'{\frac {n(r)n(r')}{|r-r'|}}}
E K S = T s [ n ] + ∫ d r V e x t ( r ) n ( r ) + E H a r t r e e [ n ] + E 11 + E x c [ n ] {\displaystyle E_{KS}=T_{s}[n]+\int drV_{ext}(r)n(r)+E_{Hartree}[n]+E_{11}+E_{xc}[n]}
V k s = V e x t ( r ) + δ E H a r t r e e δ n ( r ) + δ E x c δ n ( r ) = V e x t ( r ) + V H a r t r e e ( r ) + V x c ( r ) {\displaystyle V_{ks}=V_{ext}(r)+{\frac {\delta E_{Hartree}}{\delta n(r)}}+{\frac {\delta E_{xc}}{\delta n(r)}}=V_{ext}(r)+V_{Hartree}(r)+V_{xc}(r)}
E t o t [ n 0 ] = ∑ ε i − ∫ n 0 ( r ) [ V H a r t r e e ( r ) + V x c ( r ) ] d 3 r + E H a r t r e e [ n 0 ] + E x c [ n 0 ] {\displaystyle E_{tot}[n_{0}]=\sum \varepsilon _{i}-\int n_{0}(r)[V_{Hartree}(r)+V_{xc}(r)]d^{3}r+E_{Hartree}[n_{0}]+E_{xc}[n_{0}]}
E x c L D A [ n ] = ∫ n ( r ) ε x c L D A ( n ( r ) ) d 3 r {\displaystyle E_{xc}^{LDA}[n]=\int n(r)\varepsilon _{xc}^{LDA}(n(r))d^{3}r}
E x c G G A [ n ] = ∫ n ( r ) ε x c G G A ( n ( r ) , ∇ n ( r ) ) d 3 r {\displaystyle E_{xc}^{GGA}[n]=\int n(r)\varepsilon _{xc}^{GGA}(n(r),\nabla n(r))d^{3}r}
E x c = ∫ 0 1 d λ U x c {\displaystyle E_{xc}=\int _{0}^{1}d\lambda U_{xc}}