Book excerpt: Quantum crystallography (QCr) is a novel scientific discipline combining quantum chemistry methods and crystal structure determination. Written by leading experts in the field, this book describes original quantum-mechanical approaches to obtain crystallographic data of enhanced value and explains how they correlate with real diffraction and scattering experiments. In particular, the book covers quantum N-representability, Clinton equations, kernel energy method (KEM), and quantum theory of atoms in molecules (QTAIM) methods and their applications in crystallographic studies. Readers will be interested in the Foreword written by Nobel Laureate Ada Yonath and the Epilogue by noted science philosopher Olimpia Lombardi.