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<DIV dir=ltr><FONT face=Arial color=#000000 size=2>Dear All,</FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2> There are currently two places on the Wien2K website that suggest it is still necessary to change the monoclinic angle to 89 or 91 deg in order for the symmetry to be recognised.</FONT></DIV>
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<DIV dir=ltr><A href="http://www.wien2k.at/reg_user/faq/monoclinic.html">http://www.wien2k.at/reg_user/faq/monoclinic.html</A></DIV>
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<DIV dir=ltr><A href="http://www.wien2k.at/reg_user/limitations/">http://www.wien2k.at/reg_user/limitations/</A></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>I understand that in the past, this problem resulted in an improper calculation of the local symmetry. However, a search of the mailing list finds an email from 2005 (thread 'new version') suggesting that the problem with the angle may have been fixed (i.e. no longer necessary to put the angle near 90deg). I have run some tests with B2/m structures containing angles of 107deg (beta-TiO2), 114deg (ICSD entry for CrI2), and 110deg. In all cases the program sgroup found the correct symmetry, and 'symmetry' appeared to produce an appropriate output. </FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>If this is fixed, perhaps a note on the website that 'versions of Wien2K after x.x.x' calculate the symmetry without the need to change the angle would be useful. I spent some time trying to set the angle back and forth, and fooling around with RMTs, that seems to have been unnecessary.</FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>As I understand it, I should therefore be able to trust the calculation for (e.g.) B2/m structures, excluding other user errors?</FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>As a note for those with C-centred monoclinic lattices, the program PowderCell (freeware) is very useful for converting to a B setting or any other cell setting you would like (and between most group/subgroup relationships listed in the international tables for crystallograpy v.4).</FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2><A href="http://www.ccp14.ac.uk/ccp/web-mirrors/powdcell/a_v/v_1/powder/e_cell.html">http://www.ccp14.ac.uk/ccp/web-mirrors/powdcell/a_v/v_1/powder/e_cell.html</A></FONT></DIV>
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<DIV dir=ltr><FONT face=Arial size=2>Craig</FONT></DIV></DIV>
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