The theory of the crystal field and optical spectra of impurity ions with an empty d-shell by Vonsovsky C . In. and its co-authors is a unique and in-depth study that will open the door to the world of physics and chemistry for students, graduate students and professionals in the field of materials science and spectroscopy . This publication is an indispensable tool for those who are interested in the optical properties of materials and their application in various fields of science and technology. The book focuses on crystal field theory, which explains how the interaction between ions and the surrounding lattice affects the energy levels of electrons in atoms. The authors examine in detail how this interaction leads to the formation of optical spectra of impurity ions, especially those with an unfilled d-shell. This makes the book especially valuable for researchers working in the field of photonics, laser technology and the creation of new materials with specified optical properties. The book will be of interest to both undergraduate and graduate students who wish to deepen their knowledge in solid state physics and spectroscopy. Specialists working in laboratories engaged in the study of optical properties of materials will also find in this publication a lot of useful information. Vonsovsky and his team present the material in such a way that even complex concepts become accessible to understanding, which makes the book attractive to a wide audience. The topics raised in the book cover not only theoretical aspects, but also practical applications, which makes it especially relevant in the light of modern scientific research. The authors pay attention to such issues as the influence of crystal symmetry on optical properties, the mechanisms of interaction of light with matter and the role of impurity ions in the creation of new functional materials. These aspects make the book an important contribution to the development of science and technology, and also emphasize the importance of the crystalline field in various fields. The writing style of Vonsovsky and his co-authors is clear and logical, which allows the reader to easily follow the course of thought of the authors. They use many examples and illustrations, which helps to better understand complex concepts. The book is not only informative, but also fascinating, which makes the reading process enjoyable. Vonsowski, known for his work in physics and chemistry, demonstrates his experience and in-depth knowledge, which gives the book additional value. If you are looking for literature that will help you understand the intricacies of optical spectra and the crystalline field, then this publication will become your reliable companion. It can be the basis for your further research or just an interesting reading for those who want to expand their horizons in science. The book "Theory of the crystalline field and optical spectra of impurity ions with an empty d-shell" is not just a textbook, but a real find for everyone who seeks to understand the complex mechanisms of interaction between light and matter. Thus, this edition not only enriches the reader's knowledge, but also inspires new discoveries and research in the field of physics and materials science. Do not miss the opportunity to plunge into the world of the crystalline field and discover new horizons of science together with Vonsovsky and his team!