Ab initio structure determination of monoclinic 2,2-dihydroxymethylbutanoic acid from synchrotron radiation powder diffraction data: combined use of direct methods and the Monte Carlo method.
The crystal structure of 2,2-dihydroxymethylbutanoic acid (C(6)H(12)O(4)) in monoclinic form has been determined ab initio from synchrotron radiation powder diffraction data. Two O and five C atoms were first derived by direct methods. Two missing O atoms and one C atom were found by the Monte Carlo method without applying constraint to their relative positions. Positional and isotropic displacement parameters of these non-H atoms were refined by the Rietveld method. Molecules are linked by hydrogen bonds and they make sheet-like networks running parallel to the (010) plane. The Monte Carlo method is demonstrated to be a powerful tool for finding missing atoms in partially solved structure.
Ceramics Research Laboratory, Nagoya Institute of Technology, Asahigaoka, Tajimi 507-0071, Japan.
Y
Y
Tanahashi
H
H
Nakamura
S
S
Yamazaki
Y
Y
Kojima
H
H
Saito
T
T
Ida
H
H
Toraya