Base (chemistry) Base (chemistry) In chemistry, bases are substances that, in aqueous solution, release hydroxide (OH) ions, are slippery to the touch, can taste bitter if an alkali, change the color of indicators (e.g., turn red litmus paper blue), react with acids to form salts, promote certain chemical reactions (base catalysis), accept protons from any proton donor or contain completely or partially displaceable OH ions. Examples of bases are the hydroxides of the alkali metals and the alkaline earth metals (NaOH, Ca(OH), etc., see alkali hydroxide and alkaline earth hydroxide). These particular substances produce hydroxide ions (OH) in aqueous solutions, and are
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