In contrast to many quantum chemistry books, the relevant properties of atoms and molecules become part of the discussion immediately, and concepts are introduced at a concrete level and then generalized, and put in mathematical form at a later stage in the presentation. The goal is to establish the fundamental principles of quantum chemistry and their consequences in a rigorous way while not delaying the discussion of molecular properties until the end. This approach is based on the experience that a concrete verbal description paves the way for a more fundamental, mathematical approach.

The design goals of Quantum States are to:

• Make the concepts and methodologies of quantum chemistry accessible and meaningful to all students.
• Develop an understanding of atomic and molecular properties in terms of quantum chemistry.
• Establish the fundamental principles of quantum chemistry and their consequences in a rigorous way while not delaying a discussion of molecular properties until the end.
• Encourage the development of information processing, critical-thinking, and problem-solving skills.
• Set the challenge for each assignment at a level that encourages the growth of critical-thinking and problem-solving skills, yet that can be achieved reasonably, though not always easily, by a student learning team facilitated by a master learner, the instructor.

Quantum States is suitable for a one-semester undergraduate or graduate course and can be part of a two-semester sequence in physical chemistry. It was developed with partial support from the National Science Foundation through grant NSF DUE #0127291.