Open AccessNormal‐mode analysis of the structures of perovskites with tilted octahedra. Erratum
Author(s) -
Darlington C. N. W.
Publication year - 2002
Publication title -
acta crystallographica section a
Language(s) - English
Resource type - Journals
eISSN - 1600-5724
pISSN - 0108-7673
DOI - 10.1107/s0108767302004695
Subject(s) - octahedron , mode (computer interface) , distortion (music) , oxon , crystallography , table (database) , transverse plane , physics , condensed matter physics , mathematics , chemistry , geometry , crystal structure , structural engineering , computer science , engineering , biology , amplifier , optoelectronics , cmos , neuroscience , operating system , data mining
There is an error in the mode assignment for hettotype 9, [ a − b + a − ], discussed in the paper by Darlington [ Acta Cryst. (2002). A58, 6671 ], which has been pointed out by Dr Kevin Knight, Rutherford Appleton Laboratory, Didcot, Oxon, England. In this paper, a mode involving displacements of the anions of hettotype 9 was labelled [(½, 0, ½), M 1 ] rather than [(½, 0, ½), M 2 ]. Both modes involve plus‐like distortion of the octahedra. In the corrected Tables 1–4 shown below, this mode, which is only found in hettotype 9, has been labelled K 2 rather than H 2 . Therefore, there are not seven but eight normal modes of the cubic phase required to describe the displacements found in the nine hettotypes considered. The weights of K 2 in all the materials examined in the original paper with the structure of hettotype 9 [labelled W ( H 1 ) in the original Table 4] are correct, unaltered by the change in the labelling of the mode. It should be noted that [(½, 0, ½), M 2 ] is a longitudinal mode – the seven other modes are all transverse. The weights of K 2 are not significantly different from zero in the 15 structures examined.