Lucy Mensing arrived in Göttingen while matrix mechanics was taking shape and she took full advantage of having a front row seat for these developments. She wrote two important papers on the new quantum mechanics during the year following her PhD and co-authored another one. She wrote the first one in Göttingen but the second and the third at least partly after she had gone back home to Hamburg (where her co-author Pauli was still based in 1926, although he also visited Göttingen and Copenhagen). She was the first to apply the new quantum mechanics to diatomic molecules, which she had already written a paper about in the context of the old quantum theory in 1923-24 in Hamburg (which was only published right before the one on the new quantum quantum mechanics)