In 1939, he married Camilla Lattes, also known as Lilla, a teacher who would collaborate with him in a well-known book on atomic and molecular physics, Physics of Atoms and Molecules (1959). Appendix III of this book presents an elementary description of the collision of two charged particles, which was used by Richard Feynman in lectures that have been published as Feynman's Lost Lecture: Motion of Planets Around the Sun. An expanded version of this book was subsequently published as Basic Physics of Atoms and Molecules (1972).