Re: [ccp4bb] Two SGs in one droplet?

2016-11-01 Thread Carter, Charlie
] Sent: Friday, October 28, 2016 9:36 AM To: CCP4BB@JISCMAIL.AC.UK<mailto:CCP4BB@jiscmail.ac.uk> Subject: Re: [ccp4bb] Two SGs in one droplet? I've seen this kind of thing before. Case 1: two crystal forms in the same droplet, C2 and C222. If you looked closely, you could tell them apart

Re: [ccp4bb] Two SGs in one droplet?

2016-11-01 Thread Rangana Sanjeewa
Hi, I see this case as an example of Order-Disorder structures. This theory was developed by Dornburger-Schiff back in 1950s and very well documented. According to this theory, it is structurally possible to have P1 and C2 (in this case) and there should be a structural transformation between the

Re: [ccp4bb] Two SGs in one droplet?

2016-10-31 Thread Sam Tang
Dear all Thanks a lot for the numerous input which is highly appreciated. I should provide some updates as to what I have done on these two crystals / datasets. I processed both datasets with HKL2000 as well as imosflm. Both softwares give (essentially) the same unit cells as in the first

Re: [ccp4bb] Two SGs in one droplet?

2016-10-28 Thread Phoebe A. Rice
To: CCP4BB@JISCMAIL.AC.UK Subject: Re: [ccp4bb] Two SGs in one droplet? I've seen this kind of thing before. Case 1: two crystal forms in the same droplet, C2 and C222. If you looked closely, you could tell them apart and I was pretty good at getting a high percentage of the desired space group

Re: [ccp4bb] Two SGs in one droplet?

2016-10-28 Thread Roger Rowlett
I've seen this kind of thing before. Case 1: two crystal forms in the same droplet, C2 and C222. If you looked closely, you could tell them apart and I was pretty good at getting a high percentage of the desired space group by looking at the crystal forms. The C2 form diffracted better, so I

Re: [ccp4bb] Two SGs in one droplet?

2016-10-28 Thread Harry Powell
Hi Something I'd do is try different programs for the indexing to see if you get both choices with any programs - Mosflm & XDS will give you the 44 characteristic lattices and cell parameters by default (so you can easily see if anything like the C2 cell is a straightforward transformation of

Re: [ccp4bb] Two SGs in one droplet?

2016-10-28 Thread Bert Van-Den-Berg
From: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> on behalf of Sam Tang <samtys0...@gmail.com> Sent: 28 October 2016 14:13 To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] Two SGs in one droplet? Dear all Sorry for going a bit off-topic in this thread. May

Re: [ccp4bb] Two SGs in one droplet?

2016-10-28 Thread David Briggs
Hi Sam, Yes. I've had 2 different crystal forms from the same drop. C2 vs C2221. Completely different packing, despite that fact that 2 of the cell edges were within an angstrom or two of each other. In the above case, I soaked ligand into the crystals, one form had ligand bound, one didn't,

Re: [ccp4bb] Two SGs in one droplet?

2016-10-28 Thread Artem Evdokimov
Good morning, 53 x 2 = 106 79 x 2 = 158 Awfully close to 156 and 105 in the C-group. Are you sure there is no tricky twinning or faulty indexing of some sort - in either of these space group assignments? On the other hand, I have seen two different habits and different spacegroups growing from

[ccp4bb] Two SGs in one droplet?

2016-10-28 Thread Sam Tang
Dear all Sorry for going a bit off-topic in this thread. May I seek your advice as on whether you have experienced that crystals being obtained from the same droplet, looking alike under microscope (rod shape) and in fact growing possibly from a same nuclei, give two space groups after indexing?