I'm using the biblatex-chem bundle by @Joseph Wright. It works fine for entries in my bibliography that have three or fewer authors. But if there are four authors, instead of getting the numeric superscript, I get the superscripted indentifier and the warning "citation "x" on page 5 undefined on input line 97". There are no discrepancies or spelling mistakes in my code and .bib file (I checked and checked). The problem goes away when I remove a couple of authors. That doesn't seem like something I should do to my bibliography. Is there some other fix or a reason why this occurs?

Here is my preamble etc. :








and example of a .bib entry that has this issue:

  author = {Jing Wang,Patrick J. Bisson,Joam M. Marmolejos,Mary Jane Shultz}, 
  title = {{Nonlinear interferometer: Design, implementation, and phase-sensitive sum frequency measurement}}, 
  issn = {0021-9606}, 
  doi = {10.1063/1.4997736}, 
  pmid = {28810790}, 
  abstract = {Sum frequency generation (SFG) spectroscopy is a unique tool for probing the vibrational structure of numerous interfaces. Since SFG is a nonlinear spectroscopy, it has long been recognized that measuring only the intensity—the absolute square of the surface response—limits the potential of SFG for examining interfacial interactions and dynamics. The potential is unlocked by measuring the phase-sensitive or imaginary response. As with any phase, the phase-sensitive SFG response is measured relative to a reference; the spatial relationship between the phase reference and the sample modulates the observed interference intensity and impacts sensitivity and accuracy. We have designed and implemented a nonlinear interferometer to directly measure the phase-sensitive response. If the phase of the reference is known, then the interferometer produces an absolute phase of the surface. Compared to current configurations, phase accuracy and stability are greatly improved due to active stabilization of the sample-reference position. The design is versatile and thus can be used for any system that can be probed with SFG including buried interfaces and those with high vapor pressure. Feasibility and advantages of the interferometer are demonstrated using an octadecyltrichlorosilane film on fused silica.}, 
  pages = {064201}, 
  volume = {147}, 
  journal = {The Journal of Chemical Physics}, 
  year = {2017}
  • 4
    Your authors are not in the correct format: you need to have each one separated by and in the database – Joseph Wright Oct 17 '19 at 15:01
  • See for example tex.stackexchange.com/q/36396/35864. Correct would (probably - double check that) be author = {Jing Wang and Patrick J. Bisson and Joam M. Marmolejos and Mary Jane Shultz},. – moewe Oct 17 '19 at 15:50
  • My bibliography file was exported in this current format (I use ReadCube papers for my library which exports these files.) It would be an arduous task to go through all the entries and insert "and" everywhere. Is there some clever way to fix this that doesn't involve manually changing the .bib file? – chemistN Oct 17 '19 at 16:01
  • 1
    This should really be fixed on the exporter side. Theoretically you could run a search-and-replace , -> and, but that might be error-prone. Really whoever claims this is a valid .bib export is pretty much lying to you. That said, I don't know if maybe the input in your export software is already incorrect and it produces garbage output, because it got garbage input. (Never heard of or used ReadCube). – moewe Oct 17 '19 at 16:14
  • yeah - I contacted them and they said they are working on fixing issues with their .bib exports. I guess I have to move my library to a different software. Thanks a lot for your help! – chemistN Oct 17 '19 at 16:18