Dear all, It is generally assumed that a high value of the M20 index gives a high probability that the solution is correct. I have a particular problem for which I have a couple of different solutions with M20 between 40 and 100. The problem resides in the fact that the a and c axes of the monoclinic cell are much larger (both around 20 A) than the b-axis (3-6A?) The solution depends therefore on the angular range which is taken for the indexation process. Taking the first 20 reflections with significant intensity gives a 6A b-axis with the 010 reflection as the last one in the list. Taking 5 reflections more, the length of the b-axis decreases and the 010 remains the last in the list. And so on. The compound is organic and there is not much scattering left beyond 2Theta=30degr, giving a total of 31 reflections to be used for the indexation. How to pick up the right solution between these high M20 solutions?
Thanks in advance, Arie ******************************************* A. van der Lee Institut Europ�en des Membranes (UMR 5635) Universit� de Montpellier II - cc 047 Place E. Bataillon 34095 Montpellier Cedex 5 FRANCE visiting address: 300 Av. Prof. E. Jeanbrau t�l.: 00-33-(0)4.67.14.91.35 FAX.: 00-33-(0)4.67.14.91.19 *******************************************
