Water's ionization constant stops relying on error cancellation: quantum nuclear corrections computed per dissociation, phosphate's six steps land within 0.45
Chaining machine-learning potentials, accelerated sampling and mass thermodynamic integration into one workflow brings water's autoionization constant to 14.31 against the experimental 13.93 once nuclear quantum effects are included explicitly, and the same workflow computes all six dissociation constants of phosphoric acid without changing the order-parameter definitions, cutting the mean absolute error from 2.19 to 0.45.