If Wikipedia is to be believed, then Charlotte Froese Fischer has died, aged 94. I say "if it is to be believed" because I haven't seen any independent story about it, and the wikipedia author has no profile. Still, it would be an odd thing to do, to update her page just to change some instances of "is" to "was" and include a year of death.
Like so many of this nearly-gone generation, Froese left eastern Europe due to political upheaval. Born in what is now Ukraine, in the Donetsk region, her family left the Soviet Union on the last train allowed to depart for Germany in 1929 from where, rather fortunately given what was to come, they were soon granted a visa to go and settle in Canada. Her scientific career started with her studies at the University of British Columbia where she was interested in mathematics and chemsitry. She got interested in very early computers and got a PhD position with Douglas Hartree in Cambridge. As computers got more advanced and portable programming languages, such as Fortran, appeared, she became a leader in computational chemistry, making a famous prediction, which was experimentally confirmed, that calcium can exist as a negative ion. Normally calcium forms a positive ion by losing one or two electrons, since the outermost two electrons are rather weakly bound. It turns out that subtleties of the interactions with an extra electron that gets added can lead to a surprisingly stable configuration.
I don't think I ever met her, but I remember her being mentioned as a kind of guru when I worked at Oak Ridge National Lab in Tennessee in the late 90s and she was at nearby (on an American scale) Vanderbilt University. I was working with a group who were also very computationally-minded and I think there was some overlap or discussions with her that I was never part of.
She wrote a nice autobiographical article in the journal Molecular Physics, published in 2000, which can be found online on her personal website at Vanderbilt.
