Base (chemistry) increase the hydronium (HO) concentration in water, whereas bases reduce this concentration. A reaction between an acid and base is called neutralization. In a neutralization reaction, an aqueous solution of a base reacts with an aqueous solution of an acid to produce a solution of water and salt in which the salt separates into its component ions. If the aqueous solution is saturated with a given salt solute, any additional such salt precipitates out of the solution. The notion of a base as a concept in chemistry was first introduced by the French chemist Guillaume François Rouelle in 1754. He
Quantum chemistry methods) has made it one of the most popular methods in computational chemistry. A further step can consist of solving the Schrödinger equation with the total molecular Hamiltonian in order to study the motion of molecules. Direct solution of the Schrödinger equation is called "quantum molecular dynamics", within the semiclassical approximation "semiclassical molecular dynamics", and within the classical mechanics framework "molecular dynamics (MD)". Statistical approaches, using for example Monte Carlo methods, are also possible. In adiabatic dynamics, interatomic interactions are represented by single scalar potentials called potential energy surfaces. This is the Born–Oppenheimer approximation introduced by Born and Oppenheimer in