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Computational
discovery of new zeolite-like materials
The materials [1] were identified by a Monte Carlo search of Si atom positions as the number of unique atoms, density, space group, and unit cell of the crystalline material was systematically explored. Over 2.7M unique structures were identified (ZEFSA-II).
Of the 2.7M topologically unique, energy-refined structures by GULP [2], 313.568 are no higher in energy than +30kJ/mol Si relative to quartz as judged by the SLC interatomic potential (and 585.139 are no higher than +65kJ/mol Si relative to quartz as judged by the BKS potential) and, thus, predicted to be thermodynamically accessible as aluminisilicates [3]. "Only" these selected SLC and BKS data are currently included into the PCOD (iIt should be emphasized that the BKS forcefield is not as good as the SLC).
The 313568 SLC-refined data are included into the PCOD as CIFs with file numbers between PCOD8000001 and PCOD8313568.
The 585.139 BKS-refined data are included into the PCOD as CIFs with file numbers between PCOD9000001 and PCOD9585139.
Comparisons are provided (known_cell.zip) between the IZA cell parameters and the correspondingly identified SLC- and BKS-refined models. The unit cell parameters for dSLC and dBKS are from using PLATON [4] to identify the underlying symmetries in the database structures. So the a, b, c, alpha, beta, gamma is not going to match the knowns from the CIFs in most cases. In that file you will find :
IZA information from IZA website
dSLC information from SLC database (as transformed by PLATON)
rSLC energy optimized structure from IZA, as done by SLC
dBKS information from BKS database (as transformed by PLATON)
rBKS energy optimized structure from IZA, as done by BKS
The corresponding PCOD numbers of the CIFs corresponding to known materials are provided into the file good_matches.txt.
The complete 2.7M database is available on demand but is not yet fully searchable into the PCOD.
[1] Deem, M.W., Pophale, R., Cheeseman, P.A. & Earl, D.J., "Computational
discovery of new zeolite-like materials," J. Phys. Chem. C. (2009) in press.
http://pubs.acs.org/doi/abs/10.1021/jp906984z
[2] Gale, J.D. and Rohl, A.L., Mol. Simul. 2003, 29, 291-341.
[3] Foster, M., Simperler, A., Bell, R., Friedrichs, O.D., Paz, F.A.A,
& Klonowski, J, Nature Materials 2004, 3, 234-238.
[4] Spek, A.L., J. Appl. Crystallogr. 2003, 36, 7-13.
Software ZEFSA-II : http://www.mwdeem.rice.edu/zefsaII/