Correction: An earlier version of this obituary incorrectly identified Dr. Ammon’s daughter. She is Jennifer Thomas, not Jennifer Thompson.

Herman Ammon, who had been a chemistry professor at the University of Maryland for the past 45 years, died Aug. 2 at Doctors Community Hospital in Lanham. He was 77.

The cause was a stroke, said his wife, Jane Ammon.

Dr. Ammon specialized in organic chemistry and conducted research in the field of crystallography. He and a colleague, James Stewart, set up the first X-ray crystallography center at the university, according to Janice E. Reutt-Robey, who chairs the department of chemistry and biochemistry.

Before joining the U-Md. faculty, Dr. Ammon was an assistant professor of chemistry at the University of California at Santa Cruz. He had more than 175 journal publications.

Herman Ammon was a native of Passaic, N.J., and was a 1958 graduate of Brown University in Providence, R.I. He received a master’s degree and a doctorate, both in chemistry, from the University of Washington in 1963. He was a Lanham resident.

Survivors include his wife of 55 years, Jane Winslow Ammon of Lanham; two children, Jennifer Thomas of Waldorf and David Ammon of Bowie; and three grandchildren.

— Trishula Patel