He anticipates your suffering. He knows that the transition from the deterministic world of Newton to the probabilistic world of Schrödinger is cognitively violent. He builds a scaffold for you, starting with the postulates of quantum mechanics, leading you gently through the particle in a box, and eventually handing you the keys to the hydrogen atom. By the time you derive the Schrödinger equation, you feel less like you are memorizing math and more like you are discovering the operating system of the universe.
McQuarrie treats physical chemistry as a language, not a toolbox. mcquarrie physical chemistry
Here’s a for anyone using McQuarrie’s Physical Chemistry —often considered a more rigorous but rewarding alternative to Atkins or Levine. He anticipates your suffering