Technical terms play an important role of effective queries for many users to search scientific databases. However, authors of scientific literature often employ alternative expressions to represent the meanings of specific terms, in other words, Terminological Paraphrases (TPs) in the literature for certain reasons, which leads to producing relevant documents that are not captured by conventional terms above. In this paper, we propose an effective way to retrieve “de facto relevant documents” which only contain those TPs and cannot be searched by conventional models in an environment with only controlled vocabularies by adapting Predicate Argument Tuple (PAT). The experiment confirms that PATbased document retrieval is an effective and promising method to discover those kinds of documents and to improve the recall of terminology-based scientific information access models.