Complex sentence: Robert Ghormley Parr (September 22,1921--March 27,2017) was an American theoretical chemist who was a Professor of Chemistry at the University of North Carolina at Chapel Hill.
Split into simpler sentences: Robert Ghormley Parr (September 22,1921 to March 27,2017) was a theoretical chemist. He was a chemistry professor at the University of North Carolina at Chapel Hill.