The scientist Simon Altmann, who has died aged 98, crossed the boundaries between theoretical physics, theoretical chemistry and mathematics.
Born and brought up in Buenos Aires, Argentina, he was the son of Aarón Altmann, a travelling salesman, and his wife, Matilde (nee Branover), a secretary. Simon obtained a doctorate in chemistry, while attending as many mathematics and physics lectures as he could. In 1949, as a British Council scholar, he travelled to King’s College London, studying for a second doctorate supervised by Charles Coulson, my father, who had just been appointed professor of theoretical physics. The Coulson and Altmann families have been friends ever since.
In 1948 Simon had married Bocha Liebeschütz in Buenos Aires, and in 1950 she joined him in London, where she continued her studies for a PhD in biochemistry at University College. Among the researchers and fellow students at King’s they made some lifelong friends, including Roy McWeeny, Peter Higgs and, in particular, during a difficult time for her, Rosalind Franklin, who took the famous photos that showed that DNA took the form of a double helix.
In 1952 Simon moved to Oxford University. My father had been appointed professor of applied mathematics and Simon came as his research assistant. At the Mathematical Institute they used advanced mathematical techniques, alongside the new resource of computers, to determine the shapes and structures of molecules. Their solutions, or approximations, to the equations that determine these structures could be tested by experimental chemists and crystallographers, and more often than not they were confirmed as correct.
As a student in Buenos Aires, Simon had been briefly imprisoned for his anti-Perón activities. After Juan Perón’s regime fell, the situation changed. Simon was offered and took up a post at the University of Buenos Aires in 1957; but he quickly became disillusioned with university politics, and a year later returned to Oxford.
In 1959 Simon became university lecturer in the theory of metals, transferring to the department of metallurgy (now the department of materials). The following year he started teaching at Brasenose College, where in 1964 he was elected tutorial fellow in physics.
From 1955 till his death in 1973, my father ran summer schools in Oxford that attracted chemists from all over the world and gave them insights into theoretical chemistry. Simon was always there too, equally able to make the complex processes accessible to the very mixed audiences. This introduced him to many international contacts and visiting lectureships, particularly in Rome, fostering his love of Italy.
Although substantially self-taught, Simon was an accomplished mathematician who specialised in the applications of group theory in crystallography and in understanding the structures of solids. His work on quaternions, which can be used to describe rotations around several axes simultaneously, has been used in robotics and computer graphics.
Possessed of a lifelong interest in philosophy, poetry, classical music, art and architecture, he designed a house in Italy where he spent every summer vacation he could manage. After his retirement in 1991, he published work in the philosophy of science; and he took his interest in symmetry, inherent in group theory, in unexpected directions, exploring symmetries in Renaissance paintings and publishing several papers on the history of art.
Bocha died in 2012. He is survived by their sons, Dan, Simon and Paul.