Nucleophilic Fukui function	$f^{+}(\mathbf{r})={\rho }_{N+1}(\mathbf{r})-{\rho }_N(\mathbf{r})$
Electrophilic Fukui function	$f^{-}(\mathbf{r})={\rho }_N(\mathbf{r})-{\rho }_{N-1}(\mathbf{r})$
Dual descriptor	$\Delta f(\mathbf{r})={\left(\frac{\partial f(\mathbf{r})}{\partial N}\right)}_{\upsilon (\mathbf{r})}$
Nucleophilic Parr function	$P{}^{-}(\mathbf{r})={\rho }_s^{rc}(\mathbf{r})$
Electrophilic Parr function	$P{}^{+}(\mathbf{r})={\rho }_s^{ra}(\mathbf{r})$