X-ray Diffraction Laboratory - Policies and
 Guidelines

Single Crystal Sample Analysis

The Single crystal data may be collected and analyzed at the Facility in two ways.

1. Through licensed users ('hands-on' operators of the Chemistry Staff)
2. By personnel of the X-ray Diffraction Laboratory.

Crystal Structure Determination Service

Single crystal samples should be checked with the staff of the X-ray Diffraction Laboratory for appropriate size, shape and quality. Approved samples should be properly labelled and submit together with a sample request form duly signed by respective Research Supervisors/PI.

Sample Analysis--Scheduling

The X-ray instrument and computers are available on a first-come, first-served basis. Exceptions are made on the basis of sample instability and concurrent number of samples awaiting analysis from a particular research group.

Special Sample Handling Requirements

Do not submit the crystals in containers that are not easily accessible, e.g. a round bottomed flask. Submit the samples in small cylindrical vials. Do not remove the solvents from the crystals.

Samples should be checked for sensitivities to oxygen, water, light, temperature, etc., before being submitted for analysis. Samples exhibiting one or more of these sensitivities should be submitted in two or more properly sealed containers. Samples sensitive to oxygen or water often remain more stable under a layer of solvent. Please discuss samples requiring special handling with the staff to assure the best quality results.

Structure Data Files and Reports

When a structure is considered final and complete, all necessary data (cif, tables, diagram, etc.) will be sent to the PI and the reseachers.
You are responsible for safekeeping your own released data.

Publishing, Authorship and Acknowledgements

The following guidelines should be applied to determine whether the person(s) who determine(s) a crystal structure should be included as co-authors on manuscripts. Similar guidelines are used by nearly all the other service facilities.

1. If structural information is a major part of the intellectual content of the paper, and if this information has been derived primarily by X-Ray Crystallography that utilised the expertise of the service, then the people involved should be considered as co-authors of the paper. Most papers that include geometric information from a crystal structure determined by the Manager and his group members would be included in this category. The people who performed the determination should assist in the preparation of the manuscript. The names of the co-authors involved in the determination and interpretation of X-ray data will be provided by the Manager.
2. If structural information is used only to confirm a result, which is well established by other analytical means, then only an acknowledgement for the assistance is necessary. In such cases, the Manager and those involved would be allowed to publish the structural results of the investigation independently, if desired.
3. Acknowledgements should be made for the technical assistance if provided for data collection and reduction.
4. Please include acknowledgements to the agencies that provided funding to purchase the instruments and computers.

General Policies

All users of the X-ray instruments and computers must comply with safety and legal requirements associated with these X-Rays, X-ray instrument and computers. Specifically no user may disable or modify any safety device associated with any X-ray instrument. All users of the computers must abide any non-disclosure or related agreement between NUS and any software vendors.

All laboratory policy decisions are made by the X-ray Users of the Chemistry Department. All inquiries about policy matters should be sent to the laboratory in charge.

top