Tahitian language
Creutz became a professor, the head of the Physics Department, and the head of Nuclear Research Center at the Carnegie Institute of Technology in 1948. He was also a member of the Executive Board at the Argonne National Laboratory from 1946 to 1958, and a consultant at the Oak Ridge National Laboratory from 1946 to 1958. In addition to his work on nuclear physics, he cultivated flowers and orchids at his home. He published eight papers on floral species, and named three varieties of violets after his children. One 1966 paper, published in the "New York Botanical Garden Journal" was on "Apetahia raiateensis", a rare flower found only on the island of Raiatea in French Polynesia. He travelled to Polynesia many times, and translated "Grammar of the Tahitian language" from French into English. His family served as hosts for a time to two young people from Tahiti and Samoa.