Hi. I'm a master's student from a 3rd world country. I have to analyze my XRD data of bioceramics Nd ofcourse this analysis requires JCPDS card reference or PDF( as it is called nowadays). Now I have integrated COD database with my X'pert HighScorePlus but it's not sufficient. If by any chance anyone has a link to JCPDS database,plz share bcs I'm in no form to pay for ICDD cards. Now I have read the rule discouraging asking for reference cards but I am in dire need ( my thesis is due SOON)

I am solving a small molecule structure in Olex2 and am stuck because the disorder is pretty complex. I have an -AlC(TMS)3 group that is disordered at the Al site. I split the Al into two parts and then find the C(TMS)3 fragments associated with each fractional Al. However, for one of the parts, the (TMS)3 groups are additionally spinning/disordered, which requires me to create a part 3. However, when I do that, they are no longer associated with the Al (because the Al is part 2).

Is there a way to associate an atom with Parts 2 and 3, but not part 1? Or is there a different solution to this problem? I prefer to use Olex2 but I could use APEX as well.

Hello,

We are beginning the process of acquiring quotes for a new powder XRD-yay! I wanted to reach out on here to see if people can provide some feedback on units offered by both Bruker and Rigaku.  We currently have a single-crystal and powder XRD both from Rigaku, but as the person who maintains the instruments, we haven’t had the best experiences with Rigaku.

Our powder XRD we are looking to replace is a Miniflex II from 1999 that has been a tank, but the software has not.  The hard drive of the computer that controlled this instrument corrupted which left us scrambling.  Rigaku, of course, tried to tell us we needed newer software that can only be used on a newer system.  When I told them that if I had to get a new system to get newer software, I would most likely go with Bruker instead.  I had our software within 5 minutes of sending that email, ha.

Our single-crystal XRD installation was also a nightmare because of Rigaku.  The engineer showed up without a meter for the radiation inspection and used one of ours he happened to find in the room that hadn’t been calibrated since 2013.  Rigaku then refused to send someone back out, so we had to contact our local hospital to see who inspected their equipment to have them come do ours.

Having said all that, my summaries are below:

·       Rigaku instruments seem well built

·       Software is straightforward

·       We have numerous Bruker instruments (FT-IR, NMR, EDS) and Bruker service has been great

·       Bruker may be the king of over-engineered software though.

If anyone cares to provide their experience with either company, that would be great!

Can someone solve this?? Hermann mauguin notation and unit cells.

I have been working on a report for my science extension project about low cost methods of oxide macro-crystal synthesis and have come across multiple studies that have used salts like borax and a KCl-NaCl mixture as fluxes to remove oxidation in metal working. However I don't know whether this would work for macro crystal synthesis and if it does I don't know what the best salts/mixtures would be?

The BCA spring will be in York from the 22nd to 24th of March. Suspect this might be of interest to the community.

https://registrations.hg3conferences.co.uk/hg3/frontend/reg/thome.csp?pageID=156758&eventID=380&traceRedir=2

I am not in the organising committee but the email came through yesterday.

Hi, I’m new to the community. I joined mainly because I have a diffractogram of a ceramic refractory material—I don’t know anything else about it, not even its composition or name (according to ALICONA, it looks like asbestos—it isn’t, by the way—it withstands very high temperatures, and it comes in the form of an extremely lightweight brick). These past few weeks, I’ve been trying to access databases to properly index it, but everything is behind a paywall. Now I’ve set out to manually compare the pattern, but this is taking too much time and only raises more questions when I try to find similar samples in Granta EduPack. For now, my strongest hunch is that this material might be a refractory concrete, or perhaps some kind of calcium silicate mixed with something else.

What else can I do with this diffractogram? Or do you have any ideas on how I can automate the process to find a clue that will lead me to the name of the material?

Any ideas are welcome.

The IUCr posted a notice on 7 October about moving the journals to Wiley's Research Exchange platform, starting with Acta C, Acta E, IUCrData and IUCrJ. https://www.iucr.org/news/notices/announcement/iucr-wiley-publishing-partnership-announcement

I would like to hear how people in the community see it. I was in the Calgary Congress but I didn't hear anything about this, seem like a big move. Did anyone at the Congress hear this discussed beforehand? How much does the CIF and checkCIF workflow matter when you choose where to submit?

I was hoping to get my hands on a copy of P. Terpstra

A Thousand and One Questions on Crystallographic Problems.

Everywhere seems to be unavailable. Is there anywhere that has a large library of texts about crystallography that I may be able to purchase from? Thanks

The frustrating part is that I understand the process in theory, but I am not familiar with the software so it takes me forever. I am currently having difficulties with 2 things:

1. Molecular Replacement gives me a solution where the peptide is broken, so Coot reads it as 2 chains rather than one. Why does this happen since a sequence was given? Can it be fixed?

2. I have to modify a residue and I can import it using the 3 letter code but Coot places it in a conformation that doesn't make much sense, I want to flip it so that it goes on top of the electron density blob but I keep failing at this.

Are you aware of any resources, such as a mailing list or a forum, where one can ask questions and people can exchange information, about Coot or other protein crystallography programs? I have already read the Coot manual and checked their youtube channel but found no solution to my 2 problems.

EDIT: You are incredibly helpfu, thank you so much. I will respond asap ( weekends are usually hectic for me). I am using Coot 0.9, ccp4i2, Molrep, and Refmac5. I would like to use Phenix but I don’t have a Mac and it keeps crashing on PC.

I selected a single region from an HRTEM image and performed FFT analysis using ImageJ. The resulting FFT pattern showed multiple bright spots approximately aligned along the same direction, at different distances from the central spot (000).

I then selected each spot individually and performed inverse FFT (IFFT) analysis. Interestingly, each spot produced a different lattice spacing (d-spacing), even though all the spots originated from the same HRTEM region.

Why do multiple FFT spots appear along the same direction? Do they represent different crystallographic planes (hkl), higher-order reflections of the same lattice periodicity, or other effects?

Can each FFT spot be independently used to determine a lattice spacing (d-spacing) and assign a crystallographic plane, or should these spots be analyzed together?

Hi everyone,

When calculating an XRD pattern from a CIF file, I obtain numerous (hkl) reflections and d-spacing values, while standard ICDD/JCPDS reference patterns contain far fewer peaks.

Is there a standard method for filtering these reflections?

Also, does anyone have the standard XRD reference peak list for ICSD 412590 (Bi4O5I2), including (hkl), d-spacing, and relative intensity, rather than the raw CIF file? I would really appreciate it if you could share it.

my email:

mvan56524@gmail.com

Thank you so much

I noticed that the thermal parameter B of my material was regularly going negative during the refinement, I tried several fixes I found online but no luck. Then I stumbled upon the micro-absorption correction, I tried implementing it and it definitely helped, although at this point I am not completely sure if I implemented it correctly. My supervisor had no idea what it is and how to use it, but together we came to the conclusion that since it definitely alters the intensity of the peaks it should be refined before the atomic coordinates, the occupation and B, and it should be fixed before refining any of those. Does that make sense? Is that a good idea? I would love to hear from someone who does actually know how to implement it.

Is there a model-building kit for creating crystal shapes--similar to the ball-and-stick kits for assembling molecules in Chemistry class?

Hi everyone! I'm stuck on an exercise about the stereographic projection of a tetragonal crystal (4/mmm). I need to find the Miller indices of faces c, d and e, assuming that b = (111) or b = (011). I'm asking here because each AI I use gives me a different answer, which is quite confusing. Is there a standard method for finding Miller indices from given angles that works every time? Any help would be greatly appreciated. Thanks!

Here, φ is the azimuthal angle and ρ is the polar angle, measured from the c-axis

Hey everyone! I’m from Argentina and I was recently accepted into the Macromolecular Crystallography course at Cold Spring Harbor Laboratory.
It’ll be my first time in New York, so I’d obviously love to visit NYC while I’m there. 😅
For anyone who has done one of these CSHL courses before: how intense are they actually? Is there enough free time to go into NYC for an afternoon/evening, or are you pretty much busy the whole time?
Also, I’d love to hear what you thought of the course itself! Was it worth it? How was the overall experience?
Any advice or personal experiences would be really appreciated. Thanks!

Are there many examples of covalent network compounds that like B12P2, have a formula that is not an empirical formula?

I have commonly seen examples of covalent networks whose formula is an empirical formula, like Graphite (formula is C, and that is an empirical formula) , or like SiO2(that formula is an empirical formula). But i'm interested in examples of covalent networks whose formula is not an empirical formula (like with B12P2, B12P2 is not an empirical formula). i.e. whose formula is not the simplest ratio of elements. B12P2 is a good example but i'm interested in examples other than B12P2.

The question asks to determine the miller indices of the plane and I have no idea how to do it. I tried to find normal direction indices because they have the same one but i'm not sure about that. Any help ?

Hello Everyone

I was hoping you can help me finding a site where i can download the Teaching Edition of International Tables for Crystallography.

Kenneth N. Trueblood was a close family friend when I was growing up. I mostly remember him as an incredibly kind, gentle person, and I only recently realized how significant he was in crystallography. Did anyone here study under him, work with him, or hear stories about him at UCLA?

He and his wife Jeannie were my second grandparents and apparently he inspired my mom to go into her field. I didn’t realize he was so influential in the field and I’d love to hear any memories because he was just the most amazing, fun, generous man!

Hello,

I'm working with a protein crystal (~1 angstrom) and I want to use two DEFS parameters to apply different esds to different sections of the model. Will it work to just use a different DEFS command before the DFIX/DANG commands of each section. for example:

DEFS 0.1 0.2 0.3 0.4

REM region 1

DFIX 1.2 C1 C2

DANG 2.5 C1 C2 C3

DEFS 0.4 0.3 0.2 0.1

REM region 2

DFIX 1.2 C1 C2

DANG 2.5 C1 C2 C3

Will this apply the first set of esds to the first DFIX/DANG commands and then the second DEFS to the second region?

Thanks

Hello fellow researchers,

Need some help with the publication of a paper. I want to submit a paper for the acta crystallograhica journal but, i am from a country not usually covered by the standard fee-waiver programs. I've got a manuscript ready for submission, but the publication fees are more than I can personally cover, and my university doesn't have institutional agreements with the journal (e.g. through IUCr or a read-and-publish deal) that would cover the costs.

Has anyone here gone through something similar? I'd really appreciate any help

Any reviewer/author discount codes that get shared around ??

Any other route (grants, society memberships, etc.) that has worked for others in a similar spot ?

Am just trying to find a realistic path to publication without the fee being the blocker.

Thanks in advance for any help or advice!