Aspects of Project Looking Glass Developed at NBS (now NIST) during 1980s
“In the mid 1980s Lovas and Suenram constructed a pulsed molecular beam Fourier Transform microwave (FTMW) spectrometer to study hydrogen bonded and van der Waals dimers and trimers.”
https://nvlpubs.nist.gov/nistpubs/jres/117/jres.117.016.pdf
Dr Rick Suenram microwave spectroscopy lab, in the basement of Metrology 220 building.