"Crystal growth is a science and an art"
Margaret (Peggy) C. Etter
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
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)
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
Victor G. Young, Jr., Office: 192C Kolthoff, Phone: (612) 625-6897, vyoung@umn.edu
Doyle Britton, Office:
664 Kolthoff, Phone: (612) 625-9828, britton@umn.edu
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).
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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 |
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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. Na2Mg4+XFe
2-2X 3+ Si6+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
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.
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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.
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
American Crystallographic Association
International Union of Crystallography (IUCr)
Where to order odd substances? (for all sorts of
Chemicals a really nice catalogue)
Designed by Maren Pink.
I am grateful for comments and suggestions. Please contact me (mpink@indiana.edu).