Before revision:  The formula has two versions, the chemical balance version is: equation* G( ) = \mu_eN_e( ) + \sum_{i=1^H \mu_i N_i(} ), equation* where N_e( ) is the mean number of electrons in the space included by the first hydration shell of , \mu_e is its chemical potential;
After revision:  The formula has two versions, the chemical balance version is: equation* G( ) = \mu_eN_e( ) + \sum_{i=1^H \mu_i N_i(} ),  where N_e( ) is the mean number of electrons in the space included by the first hydration shell of , \mu_e is its chemical potential;