With deep sadness, we inform the scientific community that Charlotte Froese Fischer, a Guest Researcher at the National Institute of Standards and Technology (USA) and Affiliate Professor at the University of British Columbia (Canada), passed away on February 8, 2024.

Charlotte Froese was born on September 21, 1929, in the village of Nikolayevka (later Pravdivka, now Stara Mykolaivka), Donetsk region, Ukraine. Within a few months, her family moved to Germany shortly before continuing to Canada to settle down in the province of British Columbia. Charlotte studied mathematics, applied mathematics, and chemistry at the University of British Columbia (UBC). She already published her first paper on calculated diffraction patterns of dielectronic rods at centimetric wavelengths in 1954. Her career took a turn towards atomic physics when she was accepted for a Ph.D. program at Cambridge University under the supervision of D.R. Hartree. In 1957 Charlotte defended her thesis on solving the Hartree-Fock equations with computers.  Since then, she has been widely recognized as the world-leading researcher on atomic structure calculations.

Over the next ten years, Charlotte worked at UBC while visiting various institutions during summers. In 1963, she became the first woman to be awarded an Alfred P. Sloan Foundation Research Fellowship. After marrying Patrick C. Fischer in 1967, Charlotte followed her husband to the University of Waterloo, then Penn State University, and finally Vanderbilt University, where she was primarily appointed in computer science. However, her major research has always been in the development of powerful numerical methods related to atomic structure calculations. Even after formal retirement, Charlotte never stopped working in this field – for the past 20 years, she was a Guest Researcher at the Atomic Spectroscopy Group at NIST with a few-year break when she moved back to Canada as an Affiliate Professor at UBC.

Charlotte published more than 300 papers that formed a true foundation for modern calculational atomic physics of multi-electron atoms and ions. It is impossible to overestimate her contributions to the development of multi-configuration Hartree-Fock and Dirac-Hartree-Fock methods in atomic structure. Her classic books “The Hartree-Fock Method for Atoms” and “Computational Atomic Structure: An MCHF Approach” (with T. Brage and P. Jönsson) have become the most important textbooks on this topic.

In 1990, Charlotte was elected a Fellow of the American Physical Society “For developing the numerical approach to the Hartree-Fock method for atoms; for providing benchmark oscillator strengths; for discovery of the calcium negative ion.” She was also elected a member of the Royal Physiographic Society in Lund and a foreign member of the Lithuanian Academy of Sciences. In 2015, she was awarded an Honorary Doctorate from Malmö University, Sweden.

Charlotte was a talented and generous unifier and promotor of all the post-doctoral researchers she supervised along the years, as demonstrated by the expanding Computation Atomic Structure (CompAS) international collaboration that quickly became her academic family. In the role as the natural leader of the collaboration, she has been the inspiration for so many young scientists.

Charlotte Froese Fischer will be dearly missed by all who knew her.

With deep sadness, we inform the scientific community that Don Madison, Curator's Professor at the Missouri University of Science and Technology, passed away on May 14, 2022.

Don Harvey Madison was born in Pierre, South Dakota, on January 4, 1945.  He married Lina Engel in 1966.  The couple has two children, Lisa and Kristina, as well as six grandchildren.  After graduating summa cum laude with a B.S. degree in mathematics from Sioux Falls College in 1967, Don was advised to study physics instead of mathematics and obtained his M.S. degree in 1970 and his Ph.D. degree in 1972, both from Florida State University under the supervision of W.N. Shelton.  His Ph.D. thesis, entitled "The Distorted-Wave Theory and its Application to the Excitation of the 1P states of Helium and Mercury", was the start of a highly successful career in the development of the distorted-wave approach for electron collisions with atoms and later molecules.  After a two-year  stay as a post-doctoral researcher with Eugen Merzbacher at the University of North Carolina, Don was appointed Assistant Professor of Physics at Drake University in Des Moines, Iowa, in 1974.  He was named the Levitt Distinguished Professor of Physics in 1984.  Don was highly respected at Drake, where he received several awards for both his outstanding research and teaching, including the "Centennial Scholar Award" in 1981 and the "Liberal Arts Teacher of the Year in the Sciences Award" in 1983.

Don was a highly sought-after collaborator, especially by experimental colleagues who liked to compare their measurements with his theoretical results.  They often asked for guidance regarding future investigations by using his predictions of where the most interesting physics might be found in the vast parameter space of targets, collision energies, and angular ranges.  During one of his frequent visits to other institutions, he met Klaus Bartschat at the University of Münster in Germany.  They immediately became good friends and life-long collaborators.  Don left Drake after a sabbatical tour "around the world" to join the University of Missouri at Rolla in 1988.  The position he vacated at Drake went to Klaus. 

After moving to Rolla, Don immediately started to establish new collaborations, in particular with Tim Gay and later Michael Schulz.  With Tim he continued his work on electron-atom scattering, while he (re)started his studies of ion-atom collisions with Michael.  Don also realized early on the importance of expanding his work from atomic to molecular targets, and thus generalized his codes to handle these more complicated scattering problems. He also expanded his efforts from excitation to the much more challenging ionization processes.  Together with many students, who greatly benefitted from his guidance and nearly infinite patience, Don developed sophisticated formulations and computer codes to extend the distorted-wave framework of atomic collisions for which he was widely recognized as the world's expert.  Not surprisingly, Don also received many honors at Rolla, including multiple "Faculty Excellence" and "Outstanding Professor" awards. In 1998, he was named Curator's Professor of Physics.

Don was awarded Fellowship in the American Physical Society in 1992 for "pioneering work in the calculation of cross sections, spin polarizations, and angular correlation parameters for atomic excitation and ionization by simple charges particles." He published 287 papers in highly-regarded peer-reviewed journals, gave 130 invited talks, made countless other contributions to international conferences, and was a sought-after speaker at colloquia and seminars at institutions around the world. In 2018, he was honored as the Convocation Speaker at Sir Padampat Singhania University in India.

In addition to being an excellent physicist, Don also served the scientific community with great distinction.  For many years, he was the Director of the Laboratory for Atomic, Molecular and Optical Research (LAMOR) at Rolla. He organized the 2001 ICPEAC satellite meeting on "Polarization and Correlation" in Rolla. From 1994–1998, Don was chair of TAMOC (Theoretical Atomic, Molecular, and Optical Community, a subgroup of the Division of Atomic and Molecular Physics (DAMOP) of the American Physical Society). He served as treasurer of the Gaseous Electronic Conference from 2002–2006 and helped organizing many other conferences.  Don was also a tireless advocate for physics education at all levels.  He was instrumental in establishing a special session on "Outstanding Undergraduate Research in Atomic, Molecular, and Optical Physics" in 1994, a competition that is still being held at the annual DAMOP meetings.

Most importantly, Don was a humble man, who made the world a better place.  He served on and chaired the Board of Directors of the Russell House for battered women and raised thousands of dollars for them.  Don also served as Chairman of the Board of Directors for LOVE, a local organization to help people in need. He was active in the Episcopal Church, serving on the Vestry and also as its treasurer for many years.

Don will be sadly missed by his family and his many friends and colleagues.

Klaus Bartschat

Levitt Professor of Physics, Drake University, Des Moines, Iowa (USA)

Timothy J. Gay

Cather Professor of Physics, University of Nebraska at Lincoln, Lincoln, Nebraska (USA)