Logo "Crystal growth is a science and an art"

Margaret (Peggy) C. Etter

Welcome to the Home Page of the

X-ray Crystallographic Laboratory

Department of Chemistry

University of Minnesota

XCL Advisory Committee:

Prof. Wayne L. Gladfelter, Prof. William B. Tolman, Dr. Victor G. Young, Jr.

Department of Chemistry

Institute of Technology
192C Kolthoff Hall, 207 Pleasant Street S. E.
Minneapolis, MN 55455, USA
Phone : +1 (612) 625-6897
Fax : +1 (612) 626-7541
E-mail: vyoung@umn.edu

Download Sample Submission Form

Other Sites of Interest

Exciting Upcoming Crystallographic Events:

ACA Annual Meeting Walt Disney World, Florida, USA. 28 May-2 June 2005

International School on Mathematical and Theoretical Crystallography 20-24 June 2005, Nancy (France)

Forthcoming conferences, workshops, schools and meetings concerning crystallography from the IuCr pages

XX Congress of the International Union of Crystallography Florence, Italy, August 23 - 31, 2005

ICXOM 2005 - 18th International Conference on X-ray Optics and Microanalysis. Frascati (Rome), Italy. 25-30 September 2005

International Conference on Neutron Scattering 2005, 27th November - 2nd December 2005, Sydney, Australia

The Structure Biology of Large Molecular Assemblies the 38th crystallographic course at the Ettore Majorana Centre, Erice. 9 to 18 June 2006

SAS2006 - The XIII-th International Conference on Small-Angle Scattering. Kyoto, Japan. 9-13 July 2006

PNCMI 2006 - The sixth International Workshop on Polarised Neutrons in Condensed Matter Investigations. Berlin, Germany. 25-28 September 2006

Engineering of Crystalline Materials Properties: State-of-the-Art in Modeling, Design, and Applications, the 39th crystallographic course at the Ettore Majorana Centre, Erice, 7 to 17 June 2007

Chillie, © XCL of UMN

ACA Golden Anniversary Meeting - St. Paul, MN

More pictures from the anniversary cruise

Director

Victor G. Young, Jr., Office: 192C Kolthoff, Phone: (612) 625-6897, vyoung@umn.edu

Professor emeritus

Doyle Britton, Office: 664 Kolthoff, Phone: (612) 625-9828, britton@umn.edu

Teaching Assistant

We are investigating merohedral and non-merohedral twins. Especially interesting to us is twinning connected to reversible phase transitions. CCD-based area detectors such as used in our laboratory are a superior tool for unraveling tangled reciprocal lattices of twins (see figure below).

Left: Non-merohedral Twin

h0l section for

Cp*W(NO)(OMe)(h ²-O=C(Me)CH=CPh).

Right: 'Chameleon' Twin

h0l section for

[N(CH₃)₄]₄Ge₉O₂₆H₁₂ × 14 H₂O

We have developed software (UNTWIN) that allows for correction of intensity data in the case of non-merohedral twinning. Our program has proven very useful in this endeavor and a version running on SGIs is available. A PC test version is available.

Here is a talk on twinning which was given by V. G. Young, Jr. as tutorial and workshop during the 11th Bruker-Nonius Area Detector User's Meeting in Madison, WI 2001 and a talk given at the 2001 ACA meeting in the 'Diffraction Methods in Undergraduate Education' session.

Two key publications on non-merohedral and 'chameleon' twinning are:

[N(CH₃)₄]₄H₁₂Ge₉O₂₆ × 14 H₂O. A. Tripati, V.G. Young, Jr.,G.M. Johnson, C.L. Cahill, and J.B. Parise. Acta Cryst. C55, 496 (1999).

Composition, Stability, and Structure of a New Member of the Aenigmatite Group. Na₂Mg_4+XFe _2-2X³⁺Si_6+XO₂₀, synthesized at 13-14Gpa. T. Gasparik, J.B. Parise, R.-J. Reeder, V.G. Young, Jr., W.S. Wilford. Am. Mineralogist 84, 257 (1999).

Some twinned beauties

Instrumentation:

The XCL has two Bruker-AXS platform diffractometers with CCD area detectors and sealed-tube 3-KW X-ray generators. The single crystal instruments are controlled by PC computers and are equipped with low temperature devices. An Oxford Cryostream Cooler allows us to investigate samples in a temperature range between 80 and 300 K. Data are analyzed on Windows 2000 workstations loaded with the SHELXTL V6.10 crystallographic software package from Bruker-AXS for structure solution, refinement and graphical presentation. Site-wide licenses are available for other departmental computers. In addition, program suites WINGX and PLATON, the Cambridge Structural Database (CSD), and the Inorganic Crystal Structure Database (ICSD) are available for site users.

Services:

The XCL accepts samples for structural analysis from colleges and universities, as well as from industry. The XCL specializes in samples that suffer from twinning, small size or solvent loss. Please contact us for questions concerning the submission procedure (download sample submission form).

Annually, we teach an X-ray crystallography class which covers theory and prepares students to carry out their own structural analyses. Students and postdocs with previous experience in X-ray crystallography may also become facility users.

Policies:

1) Clients of our facility receive by email a full report file and a CIF (crystallographic information file) which is required by most journals.

2) All samples are retained by our facility for one month before disposal. Should a client wish a sample returned, he or she should request it with submission.

Current User List:

Nermeen Aboelella, Jessica Allen, Bill Brennessel, Laurie Breyfogle, Eric Brown, Michael Bukowski, Jason Burney, Joon Chatterjee, Dabing Chen, Nicholas Denny, Kevin Erickson, Angela Follett, Derek Fox, Jonathan Frisch, Joe Fritsch, Sarah Michelle Gellar, Yuchuan Gong, Brendan Gordon, Glen Gullickson, Jason Halfen, Benjamin Hamilton, Chuan He, Lyndal Hill, Erin Hilton, Sungjun Hong, Robert Jilek, Sarah Kliegman, Eric Klinker, Alexey Koposov, Benjamin Kucera, Sachin Lohani, Enxian Lu, Kari McGee, Jason Myers, Bill Ojala, Paul Oldenburg, Brian Olmsted, Alicia Peterson, Anne Reynolds, Jan-Uwe Rohde, Julia Rossini, Galen Sedo, Airon Soegiarto, Victor Sussman, Dong Wang, Zhiyong Wang, Dan Wherritt, Elisey Yagodkin, John York