Danielle Leppert-Simenauer is a Data Technologist. Math Enthusiast at Thoughtworks. Colleagues describe her as "Ms. Danielle Leppert-Simenauer was a National Science Foundation Research Experience for Undergraduates (NSF REU) scholar in my laboratory during the summer of 2016. Since then, I have been in regular contact with her as I have sent her to two national conferences where she won an award for best poster at the ASME IMECE conference. We also wrote a peer reviewed journal publication together based on the intellectual contributions to our research, which was published in the high impact American Chemical Society journal Nano Letters ( https://doi.org/10.1021/acs.nanolett.7b05229 ) and which has received quite a bit of attention and citations. In this project, she worked with me on elastic strain engineering of optoelectronic properties in atomically-thin semiconductors. Danielle’s research topic was a major part of my NSF CAREER (award no. 1553987), needless to say it is both intensive and significant. Danielle is one of the best undergraduate students I have worked with, and I have mentored many undergraduate researchers as a principal investigator both in academia and at Los Alamos. A comparable student is Jason Wu who worked with me for three years, was awarded an NSF GRFP, earned his thesis-based M.S. in one year, and is now in the Ph.D. program at UC Berkeley. Even though she was only a sophomore, I would be glad to have Danielle as my Ph.D. student. This says a lot! Danielle has presented our work at the ASME IMECE 2016 and IMECE 2017 conferences in front of my colleagues from my field, and she impressed them to the point that they awarded her a best poster award in 2016! She also presented some recent work she has been helping us with at the Spring Meeting of the 2017 Materials Research Society Spring Meeting in Phoenix. Her abstract was accepted as a poster since I recommended she start a poster as she is an undergraduate. Danielle had the initiative to request a transfer from poster to presentation after consulting me, and the session organizers were so impressed that they promoted her abstract to a presentation in a few days. At MRS, student presentations are very competitive, she presented alongside professors and senior Ph.D. students (remember, she was only a sophomore at the time). This is impressive as I have been attending MRS since 2009 and I have never seen an undergraduate present in a regular research symposium. In sum, I enthusiastically encourage Ms. Leppert-Simenauer’s acceptance into any program of her choice including those outside of basic research (I'd be glad to work with her again were she to go into a Materials Science or physics/chemistry Ph.D. program). Please feel free to contact me you have further questions about Danielle. Sincerely, Michael Pettes, Ph.D. (Los Alamos National Laboratory, Materials Physics and Applications Division)"