Ivar Waller (11 June 1898 – 12 April 1991) was a Swedish professor of theoretical physics at

Uppsala University Uppsala University ( sv, Uppsala universitet) is a public research university in Uppsala, Sweden. Founded in 1477, it is the oldest university in Sweden and the Nordic countries still in operation. The university rose to significance durin ...

. He developed the theory of

X-ray scattering X-ray scattering techniques are a family of non-destructive analytical techniques which reveal information about the crystal structure, chemical composition, and physical properties of materials and thin films. These techniques are based on observi ...

by lattice vibrations of a crystal, building upon the prior work of

Peter Debye Peter Joseph William Debye (; ; March 24, 1884 – November 2, 1966) was a Dutch-American physicist and physical chemistry, physical chemist, and List of Nobel laureates in Chemistry, Nobel laureate in Chemistry. Biography Early life Born Petr ...

. The Debye–Waller factor, which he introduced in his doctoral thesis in 1925, is the definitive treatment of the effect of thermal vibrations in

X-ray crystallography X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to diffract into many specific directions. By measuring the angle ...

. He was a member of the Royal Swedish Academy of Sciences from 1945, and the Nobel Committee for Physics 1945-1972. One of his notable doctoral students was the quantum chemist

Per-Olov Löwdin Per-Olov Löwdin (October 28, 1916 – October 6, 2000) was a Swedish physicist, professor at the University of Uppsala from 1960 to 1983, and in parallel at the University of Florida until 1993. A former graduate student under Ivar Waller, Löw ...

External links

Obituary in Journal of Applied Crystallography, 1992
{{DEFAULTSORT:Waller, Ivar 1898 births 1991 deaths Swedish physicists Academic staff of Uppsala University Members of the Royal Swedish Academy of Sciences Burials at Uppsala old cemetery Members of the Royal Society of Sciences in Uppsala