X-Ray Crystallography Facility






The following is a list of the most frequently asked questions:

Whom do I contact?
What information do I need to supply?
How do I attach the proposed structure?
How should I supply my sample?
Who will collect the data?
Can I get trained to do my own structures?
How will I receive my data?
How long will it take?
How much will it cost?
Are structures submitted to the Cambridge Data Base?

Whom do I contact? - Users should contact the director to submit your samples.

What information do I need to supply? - A sample submission form is available as an editable PDF. Fill out as much of the form as possible, print it, draw a cartoon of your proposed structure in the space provided and either print and bring the form with your sample or upload it. Samples without a complete form will not be collected.

How do I attach the proposed structure? - In Adobe Acrobat XI (avaliable through Caltech IMSS) use the Custom Stamp Tool under Comment / Annotations / Add Stamp or right click / Add Image.

How should I supply my sample? - In most instances it is preferred that samples be kept in the same crystallization solvent. Removing crystal from the solvent can cause them to degrade. If the crystal are air stable bring them along with a completed sample submission form to the lab (BI110). If the crystals are air sensitive then fill out a submission form and contact XRCF staff BEFORE removing them from an inert environment. Arrangements will be made to handle your sample in the most appropriate manner.

Who will collect the data? - Unless you have been trained on the instrument and cleared to use it the XRCF staff will collect the data. Arrangements will be made to handle your sample in the most appropriate manner.

Can I get trained to do my own structures? - Yes. We encourage users to collect their own data. The first step will be to take the EHS Xray Diffraction safety training. XRCF staff will then train users in the use of the diffraction equipement and crystallographic programs. A Certificate of Training for Use of Radiation Producing Machines will need to be filled out and submitted upon completion of instrument training. See the Additional Resources page for manuals and tutorials.

How will I receive my data? - For all structures determined by XRCF staff, the files necessary for publication will be uploaded to the Caltech Reciprocal Net unless alternative arrangements have been made. Users who determine their own structures are responsible for processing and retrieving their own data as well as uploading data to the Caltech Reciprocal Net or XRCF server.

How long will it take? - Samples are generally run on a first come first served basis, although no group will be permitted to use an instrument twice in a row if there are other groups in the queue. The wait time for data collection is dependent on the number of samples above yours in the queue and is typically less than two weeks. Structure refinement is dependent on the individual sample but will normally be completed within a week.

How much will it cost? - Prices are $200 for a data collection and $200 for a structure determination (solved and refined by XRCF staff). Non-Caltech institutions should contact Michael Takase for rates.

Are structures submitted to the Cambridge Data Base? - Structures are not automatically submitted to the CCDC. The structure should be submitted to the CCDC before publication in order to obtain a deposition number. Structures can be submitted through the CCDC website. back to top




FAQ