The seventh blind test of crystal structure prediction: structure generation methods
Lily M. Hunnisett, Jonas Nyman, Nicholas Francia, Nathan S. Abraham, Claire S. Adjiman, Srinivasulu Aitipamula, Tamador Alkhidir, Mubarak Almehairbi, Andrea Anelli, Dylan M. Anstine, John E. Anthony, Joseph E. Arnold, Faezeh Bahrami, Michael A. Bellucci, Rajni M. Bhardwaj, Imanuel Bier, J.A. Bis, A. Daniel Boese, David Bowskill, James Bramley, Jan Gerit Brandenburg, Doris E. Braun, Patrick W. V. Butler, Joseph Cadden, Stephen A. R. Carino, Eric J. Chan, Chao Chang, Bingqing Cheng, Sarah Melanie Clarke, Simon J. Coles, Richard I. Cooper, Ricky Wayne Couch, Raúl Cuadrado‐Matías, Tom Darden, Graeme M. Day, H. Dietrich, Yiming Ding, Antonio G. DiPasquale, Bhausaheb Dhokale, Bouke P. van Eijck, M.R.J. Elsegood, Dzmitry S. Firaha, Wenbo Fu, Kaori Fukuzawa, Joseph Glover, Midori Goto, Chandler Greenwell, Rui Guo, J. A. Harter, Julian Helfferich, Detlef W. M. Hofmann, Johannes Hoja, John Hone, Richard S. Hong, Geoffrey Hutchison, Yasuhiro Ikabata, Olexandr Isayev, Ommair Ishaque, Varsha Jain, Yingdi Jin, Aling Jing, Erin R. Johnson, Ian M. Jones, K. V. Jovan Jose, Elena A. Kabova, Adam C. Keates, Paul F. Kelly, Dmitry V. Khakimov, Stefanos Konstantinopoulos, L. N. Kuleshova, He Li, Xiaolu Lin, Alexander List, Congcong Liu, Yifei Michelle Liu, Zenghui Liu, Zhi‐Pan Liu, Joseph W. Lubach, Noa Marom, Alexander A. Maryewski, Hiroyuki Matsui, Alessandra Mattei, R. Alex Mayo, John W. Melkumov, Sharmarke Mohamed, Zahrasadat Momenzadeh Abardeh, Hari S. Muddana, Naofumi Nakayama, Kamal Singh Nayal, Marcus A. Neumann, Rahul Nikhar, Shigeaki Obata, Dana O’Connor, Artem R. Oganov, Koji Okuwaki, Alberto Otero‐de‐la‐Roza, Constantinos C. Pantelides, Sean Parkin, Chris J. Pickard, Luca Pilia
Abstract
A seventh blind test of crystal structure prediction was organized by the Cambridge Crystallographic Data Centre featuring seven target systems of varying complexity: a silicon and iodine-containing molecule, a copper coordination complex, a near-rigid molecule, a cocrystal, a polymorphic small agrochemical, a highly flexible polymorphic drug candidate, and a polymorphic morpholine salt. In this first of two parts focusing on structure generation methods, many crystal structure prediction (CSP) methods performed well for the small but flexible agrochemical compound, successfully reproducing the experimentally observed crystal structures, while few groups were successful for the systems of higher complexity. A powder X-ray diffraction (PXRD) assisted exercise demonstrated the use of CSP in successfully determining a crystal structure from a low-quality PXRD pattern. The use of CSP in the prediction of likely cocrystal stoichiometry was also explored, demonstrating multiple possible approaches. Crystallographic disorder emerged as an important theme throughout the test as both a challenge for analysis and a major achievement where two groups blindly predicted the existence of disorder for the first time. Additionally, large-scale comparisons of the sets of predicted crystal structures also showed that some methods yield sets that largely contain the same crystal structures.