SMART Area Detector User Group Meeting
June 7-11, 1999
This year's SMART Area Detector User Group Meeting was combined
with a Charge Density Workshop and took place at the University
of Toledo. There were 32 participants from as far away as Canada
to the North, Germany to the East, New Zealand to the South and
Korea to the West. It was the desire of the organizers to make
the whole week as hands on as possible. To this end both of the
SMART instruments in the crystallography laboratory were made
available for the whole week as well as a complete computer lab.
The first two days were dedicated to charge density measurements,
the first day dealing with the experiment and data reduction,
the second to the multipole formalism and refinement. After a
general introduction by Alan Pinkerton, he discussed reasons
for requiring very low temperature data. This talk was followed
by a demonstration by the Toledo group of setting up a liquid
helium cooling device and collecting a data set at 20 K. The
subject of data collection strategy was presented by Chris Frampton
followed by discussion and demonstration by Charles Campana of
the beta test version of COSMO, a strategy organizing program.
In addition, discussion of integration of the data using the
current and projected version of SAINT was presented. The theory
of the multipole formalism was presented by Tibor Koritsanszky
and the whole group was able to get experience with the XD package
under the guidance of Tibor and Thomas Richter using 18 computers
which had been previously loaded with the programs as well as
demonstration data.
The next three days were dedicated to talks in the mornings and
demonstrations or hands on testing of new software in the afternoon.
Highlights of the presentations gave insight into the physics
behind the technology from Roger Durst, meeting the data handling
challenge from Jon Huffman, experiences using larger in-lab CCD
systems under a variety of conditions by Alan Pinkerton and Karl
Törnroos, the story of CCD detectors at synchrotron sources
by James Phillips, non-merohedral twinning by Victor Young and
non-single crystal applications (powder and samples of timber)
from Ward Robinson. Afternoons were spent exploring the latest
and beta test versions of a number of programs that were installed
in the computer lab under the guidance of Charles Campana, Ward
Robinson and Victor Young. At the same time, a number of demonstrations
were presented in the crystallography lab. The Toledo group continued
the liquid helium demonstration begun for the previous workshop.
Roger Durst demonstrated the replacement of phosphors on the
detectors and recalibration of the flood field.
In all, a great learning experience with maximum audience participation.
Alan Pinkerton |
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Rapid
Data Collection and Structure Solving at the NSLS: A Practical
Course in Macromolecular X-Ray Diffraction Measurement - April
18-23, 1999
Held at the Biology Department and National Synchrotron Light
Source, Brookhaven National Laboratory, 18- 23 April 1999
Forty-seven students attended the four-and-a-half day lecture
and laboratory course on Rapid Data Collection and Structure
Solving in Macromolecular Crystallography held at Brookhaven
National Laboratory during 18-23 April 1999. Of the students,
three were from Canada, three from UK, five from other European
countries plus New Zealand, and the rest from the USA. The student
body included two full professors, two other senior scientists,
two assistant professors, and the rest post docs or graduate
students. A summary of the course can be found at the web site
http://www.x12c.nsls.bnl.gov/rr_course/.
Two days were devoted to lectures on fundamentals and practical
details of use of software and specimen handling. The titles
of lectures and names of lecturers are:
Diffraction Geometry for the Rotation Method - Robert Sweet,
Brookhaven National Laboratory
Strategy in data collection - Zbyszek Dauter, Nat'l Institutes
of Health
Data reduction with d*Trek - James Pflugrath, Molecular Structure
Corp.
Data reduction with the HKL suite - Zbyszek Otwinowski, University
of Texas, and Wladek Minor, Univ. of Virginia
Data reduction with The DPS/Mosflm Package - Chris Nielsen, Area
Detector System Corp.
Beamline software: Optix, MARMAD - John Skinner, BNL
More beamline software: ADSC and X12-B controls - Malcolm Capel,
BNL
Frozen specimen preparation for the synchrotron - Elspeth Garman,.
Oxford Univ.
Special properties of SR: polarization, bandwidth, collimation
- Lonny Berman, BNL
Modern CCD-based x-ray detectors - Malcolm Capel, BNL
MAD structure solving - Craig Ogata, Howard Hughes Medical Inst./Columbia
Univ.
Structure solving with SOLVE - Li-Wei Hung, Lawrence Berkeley
Lab., Los Alamos National Laboratory
Structure solving with CNS - Jiansheng Jiang, BNL
On the evening of the second day, the whole course (including
some thirty instructors) moved to the NSLS for last-minute training
and to begin data collection. Half of the students had won admission
to the course by having proposed their own experimental problem,
and had brought specimens with them for data collection. The
rest of the students attended as observers and helpers. Some
students brought crystals already frozen in liquid nitrogen;
some brought them in delicate crystal-growing apparatus.
Six NSLS dipole beamlines were dedicated to use by the students
in the course, and they were used for about 60 hours, with the
students working in shifts around the clock. Nearly all of the
projects accomplished useful data collection as part of the learning
process. One of the goals of the course was to teach the students
the way that modern synchrotron and computational methods can
lead to the production of an atomic-resolution map of the structure
on the time scale of the data-collection process itself. Indeed,
one of the teams of students had produced such an electron density
map within about 16 hours of having started data collection.
Two other groups accomplished the same thing by the end of the
course.
During the two days of data collection there were continuing
tutorials in use of the software and in crystal freezing. Two
of the students participated in these: Chuck Weeks of the Hauptman/Woodward
Inst. demonstrated Shake-and-Bake and solved a heavy-atom problem
for a student who had brought otherwise uninterpretable data.
Sean Parkin of Duke helped Elspeth Garman in the crystal-freezing
lab.
This course was sponsored by a grant from the National Institute
of Health Division of Research Resources to the Brookhaven Biology
Department and National Synchrotron Light Source, and in part
by support from the Department of Energy Offices of Biological
and Environmental Research. Some financial assistance for this
course came also from Brookhaven Science Associates and Hampton
Research Corp. of Laguna Niguel, California. It was organized
by R.M. Sweet, M. Capel, L. Berman, and A. Emrick.
R.M. Sweet |
