Ove Jepsen
Ove Jepsen died suddenly on 4 January 2017 at age 73. He was an internationally recognized pioneer and beloved teacher of electronic-structure calculations. From 1979 until beyond his retirement in 2011 he worked at the Max-Planck Institute for Solid-State Research (MPI-FKF) in Stuttgart, Germany.
Born on 29 June 1943 in Copenhagen, Ove received his MSc in 1969 and his PhD in 1972 from the Technical University of Denmark under the supervision of Allan Roy Mackintosh and Allan’s former student, Ole Krogh Andersen. Ove’s thesis on the Fermi surface of ytterbium included the tetrahedron method and was published in Solid State Communications. By the 40th anniversary of that journal, Ove’s paper had become its second most cited. Together with papers from 1984 and 1994 containing improvements of the method, Ove’s thesis has now been cited 6000 times. Ove joined the Danish National Laboratory at Risø, where in 1973–75 he wrote an LMTO-ASA band-structure code that enabled fast density-functional (DF) calculations for 𝑠-, 𝑝-, 𝑑-, and 𝑓-electron materials. With it, he first demonstrated that spin-polarized DF theory accounts for the pressure-volume relations of iron in the closely-packed phases, and later he treated all elemental metals. For transition-metal surfaces, accurate DF calculations became possible thanks to Ove’s full-potential LAPW code developed a few years later when he was at NORDITA in Copenhagen. In 1978, Ove was invited by John Wilkins to Cornell University, where he met Virginia. They married in La Paz, Bolivia, and moved to Germany the year after.
At the MPI-FKF, in the new group for electronic-structure calculations, Ove became responsible for developing, maintaining, and using the codes and for teaching the students and many postdocs who over the years came from Italy, Japan, North and South America, Eastern Europe, Russia, Ukraine, India, and China. He became highly respected for his friendly, patient, and conscientious nature. Also privately, he and Virginia cared for the young scientists, and many lifelong, international friendships were formed.
The Stuttgart TB-LMTO-ASA code was probably the first DFT code made freely available. Ove was the one who showed that the transformation to tight-binding (TB) works, and the corresponding 1984 paper in Physical Review Letters became his second-most cited paper. The TB feature not only made DF calculations possible for condensed matter without 3D periodicity, but it also made band structures intelligible. This became essential as the discovery of high-temperature superconductivity in cuprates (HTSC) necessitated an improved treatment of electronic correlations. With Olle Gunnarsson and Jan Zaanen, Ove calculated the parameters of the Anderson impurity Hamiltonian, a prerequisite for the later development of the LDA+𝑈 method in the group and, eventually, for the first ab initio applications by Vladimir Anisimov et al. of dynamical mean-field theory. Also the development of electronic indicators, specifically Canonical Bands, Fat Bands, ELFs, and COHPs, were facilitated by Ove. Properties treated by Ove and collaborators included Fermi surfaces, chemical binding, magnetism, optical properties, and electron–phonon mediated superconductivity. He calculated and analyzed the electronic and phononic structure of numerous materials of current interest, most notably HTSCs, A3C60, and M𝗀B2.
Ove co-organized the 1st and 2nd Psik conferences, which took place in Schwäbisch Gmünd, Germany, in 1996 and 2000. In 2008, he was selected as Outstanding Referee for the Journals of the American Physical Society.
Ove loved and was proud of his family: Virginia, Marianne, and Charlotte. He was also proud of being a Dane. On Fanø, a sandy island outside the Danish west coast, he owned a house where he and his family spent the summer every year. Friends were very welcome. Ove also enjoyed reading a good book, traveling, playing tennis, and he was interested in art and music.
Many will miss him.
