Here is a minimal database for an ion association model, although you could remove the delta_H and analytical expressions. If you really want to make your own database, then you can add to it.SOLUTION_MASTER_SPECIES H H+ -1 H 1.008 H(0) H2 0 H H(1) H+ -1 0 E e- 0 0 1.008 O H2O 0 O 16 O(0) O2 0 O O(-2) H2O 0 0 SOLUTION_SPECIESH+ = H+ log_k 0 -gamma 9 0e- = e- log_k 0H2O = H2O log_k 0H2O = OH- + H+ -analytical_expression 293.29227 0.1360833 -10576.913 -123.73158 0 -6.996455e-005 -gamma 3.5 02H2O = O2 + 4H+ + 4e- log_k -86.08 delta_h 134.79 kcal2H+ + 2e- = H2 log_k -3.15 delta_h -1.759 kcalEND