[sdpd] Prediction - PCOD and GRINSP

[Armel Le Bail <alb...@cristal.org>]

Hi,

The PCOD was updated recently and contains now more
than 450 CIFs of predicted structures in the domain of
corner-sharing triangles/tetrahedra/octahedra :
              http://www.crystallography.net/pcod/

The combinations B2O3/SiO2 (triangles/tetrahedra) are
still in exploration by using the GRINSP program.
Already disclosed and inserted in PCOD :
   cubic : 5 hypothetical compounds
   tetragonal : 31
   hexagonal : 21
   orthorhombic : 22
   monoclinic : 153

By chemical formula, this gives :
SiB2O5 : 57 hypothetical compounds
Si3B4O12 : 32
Si4B2O11 : 28
Si2B6O13: 28
Si2B2O7 : 24
SiB6O11 : 18
SiB4O8 : 17
Si3B2O9 : 14
Si6B2O15 : 6
Si3B6O15 : 2
etc

Calculations this week-end with GRINSP :
500000 tests in triclinic cells for B2O3/SiO2
7766 solutions (not unique and including previous solutions
                        in higher symmetries)
369 new solutions (including many two-dimensionnal structures
                              to be excluded)
... to be examined one by one and added to the PCOD - if time
is found ... predictions are faster than insertion into the database !

Best regards,

Armel

PS - Thought of the week :
"Science is maturing, and the more predictable a result,
the less it needs to be published. "
by C.A. Reed
http://chronicle.com/temp/reprint.php?id=a5jy9pagwlezr86x489mrxjub1henyo

PS2 - Moreover, in ICSD, one can found only one Si/B/O compound,
a zeolite with B/Si substitution on the same atomic coordinates.
So, what to do with these ~400 hypothetical Si/B/O, apart from
loading them into a database ?-).

PS3 - Still lacking, the prediction of the synthesis feasibility...

PS4 - OK, this is a kind of senseless demonstration.



 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
     http://groups.yahoo.com/group/sdpd/

<*> To unsubscribe from this group, send an email to:
     sdpd-unsubscribe...@yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:
     http://docs.yahoo.com/info/terms/