Atkins is without a doubt the worst author you will ever read. There is almost no chemical concept that Atkins can't make unnecessarily confusing. In his execrable Physical Chemistry he's renamed nearly experiment or mathematical proof underlying the science as a "justification," which is also what he calls his plausibility arguments that argue for reasonableness but fall short of scientific proof, leaving most students wondering what is scientific fact and what is reasonable conjecture. Fortunately, in the last three revisions he's made no substantive improvements, preferring instead to play with the rendering of his utterly useless illustrations, so the text isn't likely to get worse. (He does them himself, so don't criticize them when you meet him.) Atkins is though comprehensive, which is why many instructors adopt it despite misgivings.
The absolute best quantum chemistry text is McQuarrie's "Quantum Chemistry". It is clearly written, logically ordered, and asks you to derive much of the content yourself before it presents the result in small, bite-sized steps, which will do wonders both for your understanding of quantum chemistry and for your confidence in your ability as a budding physical chemist. This will probably be out of sequence for your course, which will probably cover thermo before quantum, but if you have time and interest it would be a very good idea to work through some of McQuarrie to convince yourself that this isn't a particularly difficult or confusing subject before Atkins can throw a wrench in the works. The original 1983 edition is probably best; the 2007 version relies heavily on numerical analysis programs, which is an unnecessary distraction in a first quantum course.
The best thermo text for a beginner is probably Cengel's "Thermodynamics: An Engineering Approach". Like most engineering thermo texts, it ignores concepts specific to chemical thermo. However, it will give you a solid foundation in applying thermodynamic laws to physical systems, and again the confidence that you can actually do that, before Atkins' bluster destroys your faith in your ability to understand the subject.
McQuarrie's "Physical Chemistry: A Molecular Approach" is also good, but the quantum presentation isn't as focused as his earlier "Quantum Chemistry" and the thermo presentation is inferior to almost any engineering text you'll read (except of course for the aforementioned omissions).
If you want to learn to solve problems then (1) choose American authors over British authors (sorry Brits, but Oxford dons will blather on about the most useless tripe), (2) choose engineering or physics texts over chemistry texts (sorry chemists, but it really doesn't matter that all most chemistry students remember of PChem is that they were badly frightened by it, while most engineers and physicists will have to apply it sooner or later, and this difference in experience is reflected in the texts), and (3) buy the solutions manual and use it (but don't use it as a crutch). There aren't many truly original problems, and often once you've seen a problem solved you can easily solve a similar problem yourself.
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