Renowned physical chemist and UC Berkeley’s Aldo De Benedictis Distinguished Professor of Chemistry Phillip Geissler died at the age of 48.

“Phil was the person to call to tell him that I was accepted into the graduate program in 2008,” said David Limmer, a campus assistant chemistry professor.

According to Limmer, many classes he took while studying for his graduate degree were taught by Geissler. Limmer described Geissler as “an active mentor.”

Limmer added that he and Geissler would often spend time together with other colleagues in campus’s Pitzer Center for Theoretical Chemistry.

“Instead of being an advisor or teacher, he took on another role as a friend and a colleague,” Limmer said.

When Limmer returned to campus in 2016 as a professor, he said he reconnected with Geissler, noting that their relationship had changed since Limmer’s time as a student.

According to Limmer, much like himself, Geissler began his career at UC Berkeley as a graduate student and graduated in 2000. Following his graduation, Geissler joined campus faculty in 2003.

News of Geissler’s passing was met with an outpouring of support from the chemistry community around the world, according to Limmer.

“Phil was an amazingly supportive colleague, a witty friend,” Limmer said. “He was a very careful and brilliant scientist, he was someone you could always go to for advice. He was someone whose academic work in science was brilliant, of the utmost quality and done with so much care.”

During their free time together, Geissler loved to watch soccer, Limmer recollected. According to Limmer, during the 2018 FIFA World Cup, Geissler and Limmer would go to the bars around campus to watch the tournament play out, as Geissler rooted for Germany’s team.

Limmer said they would also spend time watching the Oakland A’s play.

Geissler was also a fan of science fiction, according to Limmer. He added that the two would often talk together about their favorite literature.

During the COVID-19 pandemic, Limmer mentioned that Geissler took up woodworking as a hobby. According to Limmer, Geissler built him a shelf, which he put on display in his living room.

“To me he was someone who was supportive in every dimension of my life,” Limmer said.