To be honest, until now, my idea about “ab initio” was: we can determine all physical and chemical properties of material using the Schrodinger equation which composes the ‘basic’ elements of nature, atoms and electrons. But I have a new idea: fundamental concepts and associated equations from where we can construct other concepts, notions, ideas, knowledge,…
Using this new notion, the Newton´s equations are the fundamental laws with which all classical physics (mechanics) is building up. Then, classical mechanics is, yes, an ab initio model. On the same way, the classical electromagnetism is an ab initio model too, because this theory makes use of the Maxwell’s equations that are fundamental equations to understand it….