Department of Chemistry & Biochemistry, University of Maryland, College Park, MD 20742

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General Policies

These policies have been set after discussion with the Shared Instrumentation Committee and the Chair of the Department in order to provide quality crystallographic services to departmental users as well as to external researchers.

Single crystal experiments are performed on a first come first served basis except in case of special circumstances (e.g. stability). The latter should be discussed with the PI.


Scheduling of powder experiments is subject of available time and has to be done (by all users) using sign-up sheets in the lab. ON-LINE booking is coming in July 2008.


Work for departmental users has priority over work for outsiders.


The crystallographer has some flexibility in scheduling experiments and performing structure refinement in order to optimize the productivity.


Every crystal structure is considered as being important and all possible effort will be made to solve and finalize refinement in reasonable amount of time. However some difficult cases may require considerable effort and longer time.



Currently there are flat charges per sample for single crystal experiments and hourly charges for the use of powder diffractometers. Experiment setup, sample preparation and training performed by PI are charged additionally. The charges are prorated based on the type of funding is used. The schedule of the charges is available on request.



Co-authorship guidelines that are expected to follow in the X-ray crystallographic laboratory are in agreement with ACA regulations and with policies accepted at the majority of crystallographic laboratories.


The crystallographer should be considered for co-authorship when the structural information is an important part of the paper and structural information has been derived mainly from the diffraction data.


If structure determination was used only to confirm information obtained by other means (NMR, mass spec, etc.) and no structural details will be given in the paper, only acknowledgment is more appropriate. An acknowledgement may also be sufficient in case of routine experiment and straightforward structure determination.


It is also common practice to acknowledge funds used to purchase the equipment.


Safety and Lab Access

Users of X-ray diffractometers (both single crystal and powder) may request access to the X-ray lab and permission to work on x-ray equipment.


There are two levels of the lab access. Individual user is allowed to work on the instrument only under the supervision of an authorized user or the crystallographer (PI). In certain cases the individual user might also be granted lab access (typically during work days only). Authorized user is one who can access lab anytime and is allowed work on the instrument independently.


Only users that will conduct powder diffraction experiments on the regular basis should request the authorized user access (typically not more that 1-2 students from one research group). It is unlikely (still possible) that the authorized user access will be granted for work on the single crystal diffractometer.


Users of the X-ray equipment MUST comply with safety requirements associated with these instruments. They MAY NOT disable or modify  safety devices on any X-ray instrument at any time.


In order to become x-ray lab user please follow guidelines below:




INDIVIDUAL USER is one who can work in the x-ray lab under supervision of an Authorized User or PI.

IN order to become an individual user take and complete safety course ( with the radiation safety office ( Dosimetry will then commence with radiation safety certificate and a temporary radiation badge to be replaced with a routine badge once person has been added to system and new dosimetry cycle has begun.

NOTE that the certificate (or its copy) and the badge have to be kept in the x-ray lab.




When radiation safety badge and certificate are issued, user can undergo training. Upon successful completion of this step said person is then an INDIVIDUAL USER and can work in X-ray Lab under supervision of an Authorized User or PI. No lab access is granted for the individual users. Please visit Radiation Safety web page for more information. NOTE that any person working in a radiation producing laboratory must pass Step 1. Since Fall 2008 lab is split into common area and equipment room. Only individual entering equipment room(s) are required to have radiation safety badges.




AUTHORIZED USER is one who can work in the x-ray lab independently.

Personnel that wish to use instruments on their own must first have in-house/external safety training, then fill out the proper forms, submit to PI for authorization in this radiation producing laboratory and then finally submit them to the Radiation Safety office. Novice users who never used x-ray equipment before are required to have several month of experience (as individual users) prior to applying for Authorized user status. Therefore, users are required to present form for appropriate signatures, create photocopy for user, photocopy for this laboratory and then user should send/carry original to the Campus Radiation Safety Officer (Steve Hand - 2124 Chemical and Nuclear Engineering Bldg). Download form here "TRAINING AND EXPERIENCE FORM FOR USERS OF RADIATION PRODUCING DEVICES".



Upon successful completion of above steps and approval has been received from the campus Radiation Safety Officer said person is then an AUTHORIZED USER and shall be granted access and added to the laboratory entry system on the submission of  X-ray Lab Access FormThe authorized user is allowed to work independently in the lab including nights and weekends. Please visit Radiation Safety web page for more information.




The following items/documents must to be submitted to/kept in the lab:



  - Dosimetry badge (all users);
- Certificate of Training (original or copy) issued by radiation safety office (all users);
- X-ray Lab Access Form - for authorized users;
- Trainning & Experience Form - for authorized users.

Housekeeping & Managing Data

As a part of safety practice it is mandatory that users leave working place (diffractometers, benches, etc.) clean and organized after experiment is done.

Anyone who finds place in unacceptable conditions shall record conditions and time in the log book and inform the PI.

Users that do not comply with the above requirements (repeatedly) will be charged for cleaning work place by lab staff and might be suspended from work in the lab.


Users of the powder diffractometer are responsible for logging into the X-ray lab notebook time used for experiment and data treatment.