错误：
引文 'Mosconi' 在第 1 页 undefined
和
存在未定义的引用。
问题：参考文献未加载且引用未定义（但即使在参考文献成功加载后，该问题仍然出现过一次）。
我已经做了什么：
- 设置我的快速构建以包含 PdfLaTeX + Bib（la）tex + PdfLaTeX (x2) + 查看 Pdf
- 确保 bib 文件和 latex 文件位于同一文件夹中。
LaTeX 主体：
\documentclass{article}
\usepackage{graphicx}
\usepackage{amsmath}
\usepackage[margin=3.5cm]{geometry}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{multicol}
\usepackage{natbib}
\begin{document}
\title{\textbf{Literature Review}}
\author{James A. Walsh}
\maketitle
\begin{multicols}{2}
ah \cite{Mosconi}
\bibliography{readcube_export}
\bibliographystyle{plain}
\end{multicols}
\end{document}
然后是bib文件（readcube_export.bib）：
@article{Mosconi,
volume={117},
year={2013},
doi={10.1021/jp4048659},
journal={J Phys Chem C},
number={27},
abstract={ We computationally investigate organometal {CH3NH3PbX3} and mixed halide {CH3NH3PbI2X} perovskites {(X} = Cl, Br, I), which are key materials for high efficiency solid-state solar cells. {CH3NH3PbX3} perovskites exhibited the expected absorption blue shift along the I → Br → Cl series. The mixed halide systems surprisingly showed the {CH3NH3PbI3} and the {CH3NH3PbI2Cl} (or {CH3NH3PbI3–xClx)} perovskites to have similar absorption onset at ∼800 nm wavelength, whereas {CH3NH3PbI2Br} absorbs light below ∼700 nm. To provide insight into the structural and electronic properties of these materials, in light of their application as solar cell active layers, we perform periodic {DFT} calculations on the {CH3NH3PbX3} and {CH3NH3PbI2X} perovskites. We find a good agreement between the calculated band structures and the experimental trend of optical band gaps. For the mixed halide perovskites our calculations show the existence of two different types of structures with different electronic properties, whose relative stability varies by varying the X group. For these systems, the calculated formation energies decrease in the order I \{\textgreater\} Br \{\textgreater\} Cl, in line with the observed miscibility of {CH3NH3PbI3} and {CH3NH3PbBr3} compounds, while suggesting a comparatively smaller chlorine incorporation into {CH3NH3Pb(I1–xClx)3} compounds. We also show that Cl atoms preferentially occupy the apical positions in the {PbI4X2} octahedra, while Br atoms may occupy both apical and equatorial positions, consistent with reported lattice parameters. The interplay of the organic and inorganic components of the perovskites, possibly mediated by hydrogen bonding between the ammonium groups and the halides, seems to be the key to the observed structural variability.},
pages={13902-13913},
issn={1932-7447},
author={Mosconi, Edoardo and Amat, Anna and Nazeeruddin, Md. K and Gr{\"a}tzel, Michael and Angelis, Filippo},
file={C:\Users\James\Google Drive\2017\2017 Honours Project\Literature Review\jp4048659.pdf;C:\Users\James\Documents\ReadCube Media\Mosconi et al-2013-The Journal of Physical Chemistry C - supplement.pdf},
title={{First-Principles} Modeling of Mixed Halide Organometal Perovskites for Photovoltaic Applications}
}
正如您所看到的，bib 文件已经由原始导出器（ReadCube）正确格式化（我认为），包已包含在内，引用了正确的 ID，文件名也是正确的。
我可能做错了什么？
答案1
示例没有使用 BibLaTeX，而是使用包natbib。因此，构建应该使用 BibTeX，命令顺序：
pdflatexbibtexpdflatexpdflatex