Transcript Document 7162466

Building a teaching course
around crystallographic freeware
Lachlan M. D. Cranswick - CCP14 Project, UK and
Geochemistry - Lamont-Doherty Earth Observatory of
Columbia University, Palisades, New York, USA.
E-mail: [email protected]
WWW: http://www.ldeo.columbia.edu/~lachlan/
WWW: http://www.ccp14.ac.uk/
Main aim of this talk
• Emphasize that there is a range of high quality freely available
software packages that can be useful for simple to advanced
crystallographic teaching of single crystal and powder
diffraction
• Encourage teachers of crystallography to consider continually
checking for new software tools that can help teach not only
scientific skills, but career employable scientific skills.
• Suggest that crystallographic teaching courses should also be
training students on a diverse range of crystallographic
software and encouraging versatility in the attitudes of
students to continually search and use new tools and
techniques as a continuing process of self education.
Slide 2
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Notes Free Zone - they are on the web
http://www.ccp14.ac.uk/poster-talks/aca2001/
Slide 3
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Why bother considering a variety
of modern software? (1 of 4)
One consideration for modern
crystallographic teaching is to
minimize the risk of producing
Crystallographic Cannon Fodder;
and maximize (i) employability of
graduates and (ii) intellectual
opportunities for obtaining an
exciting scientific career.
Slide 4
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Why bother considering a variety of modern software? (2 of 4)
Path of Most
Resistance?
Using a variety of “state-ofthe-art” tools can improve
students’ versatility by
demonstrating different
pathways to tackle
crystallographic problems.
– When to use a subtle
crystallographic
nutcracker
– When to unlock the
sledgehammer cabinet
– When to declare that
Defcon 1 has been
activated!
Slide 5
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Why bother using and teaching a variety of modern software? (3 of 4)
Crystallographic Weaponry 101
• Provide both
– i) a rigorous grounding in
the theory and
– ii) the want in students to
find and use the best
software tools for the job
• Provide for chemists and
scientists who use
crystallography as a tool
within a larger project and
context.
Slide 6
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Why bother using freely
available software? (4 of 4)
Much freely available software is state of the art
in both algorithms and usability - (GUIs)
• Lessons can concentrate on the crystallography
(rather than learning text editors)
• Can be installed on as many computers as you
want - where-ever you like
• Students can take programs home and use on
their personal computers (negate software
piracy problems)
• Students can use the software as an initial
research tool kit
Slide 7
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Crystallographic
Weaponry 102
Agenda for Some Examples
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Automatic structure solution and refinement: “Platon / System S”
Spacegroups and Symmetry using “Gretep”
Scattering: “scatfac”, “dispano”, “poudrix”, “powder cell”
Peak “profiles” and peak profiling using “XFIT”
Powder Indexing using “Crysfire” and “Chekcell”/
Systematic absences in PXRD using “Chekcell”
Complete single crystal analysis methods via “WinGX”
Guided crystal structure refinement using “Crystals”
Structure validation using “Platon”
Slide 8
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Hopefully Platon / System S demonstration worked!
(Ton Spek - http://www.cryst.chem.uu.nl/platon/)
• Fully automatic
structure solution
• Can show students
how routine service
crystallography can
function
• Give them training on
a powerful tool for use
in their research or
employment.
Slide 9
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Platon / System S for UNIX / Linux / FreeBSD
(Ton Spek - http://www.cryst.chem.uu.nl/platon/)
• Concentrate on the problematic - go quickly
through the routine; (transparent links to other programs)
– Structure Solution:
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Shelxs: http://shelx.uni-ac.gwdg.de/SHELX/
Dirdif: http://www-xtal.sci.kun.nl/xtal/documents/software/dirdif.html
Sir: http://www.ba.cnr.it/IRMEC/SirWare_main.html
Crunch: http://chemb0b.leidenuniv.nl:80/~rag/
– Autobuilding of structures:
• EXOR, Dirdif, Sir, Crunch
– Structure Refinement:
• Shelxl: http://shelx.uni-ac.gwdg.de/SHELX/
– Validation, Fourier Maps, Addsym, Squeeze, etc.
Slide 10
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Gretep structure plotting / symmetry
(by Jean Laugier and Bernard Bochu)
(http://www.ccp14.ac.uk/tutorial/lmgp/)
• Freely available for anyone
• Very easy to use, including
– Click and drag to rotate,
translate, zoom
– Draws symmetry operators
labels
– Loads common file formats Shelx, CIF
– Includes I.D. Browns
GETSPEC
– Can save all plotted information
(labels, fonts, etc) into Gretep
files
Slide 11
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Gretep: Showing symmetry operators (1)
Slide 12
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Gretep: Showing symmetry operators (2)
Slide 13
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Gretep: Each fragment with a different colour
Slide 14
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
If time limited: more chance to get your points
across to students if examples are interactive
Slide 15
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Scatfac for interactively investigating
scattering factors (http://www.ccp14.ac.uk/tutorial/lmgp/)
Slide 16
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Dispano for Anomalous Scattering factor
display (http://www.ccp14.ac.uk/tutorial/lmgp/)
Slide 17
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Dispano for Anomalous Scattering factor
display (http://www.ccp14.ac.uk/tutorial/lmgp/)
Slide 18
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Poudrix powder pattern calculation
With Anomalous Dispersion - (Brenann and Cowan or Sasaki)
(http://www.ccp14.ac.uk/tutorial/lmgp/)
Slide 19
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
PowderCell powder pattern calculation
(by Werner Kraus and Gert Nolze)
(http://www.ccp14.ac.uk/tutorial/powdcell/)
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Can model multiple phases for
quantitative analysis or modeling
impurities
Interactively modify atom
occupancies and observe changes
in the powder pattern
Move atoms using point and click
then see the change in the powder
pattern
Overlay a calculated powder
pattern with raw diffraction data.
Whole pattern unit cell refinement
Slide 20
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
PowderCell - interactively moving atoms (1 of 3)
(http://www.ccp14.ac.uk/tutorial/powdcell/)
Slide 21
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
PowderCell - interactively moving atoms (2 of 3)
(http://www.ccp14.ac.uk/tutorial/powdcell/)
Slide 22
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
PowderCell - interactively moving atoms (3 of 3)
(http://www.ccp14.ac.uk/tutorial/powdcell/)
Slide 23
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
XFIT Peak Profiling
by Alan Coelho and Bob Cheary
(http://www.ccp14.ac.uk/tutorial/xfit-95/)
• Robust peak fitting
• Multiple Patterns
• No soft limit on the
number of peaks that
can be refined at once
• Can handle alpha 1/2
• Cons: does not have a
standard GUI interface
Slide 24
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
XFIT Peak Profiling - 1 of 4
Load Data
Slide 25
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
XFIT Peak Profiling - 2 of 4
Zoom up
Slide 26
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
XFIT Peak Profiling - 3 of 4
Insert Peaks
Slide 27
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
XFIT Peak Profiling - 4 of 4
Fit Peaks (auto-Marquardt damping)
Slide 28
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Crysfire Powder Indexing
Robin Shirley (http://www.ccp14.ac.uk/tutorial/crys/)
• Imports XFIT and
other peak formats
• Links to 8 different
indexing programs
– Ito, Dicvol, Treor,
– Lzon, Taup, Fjzn
– Losh, Kohl
• One line per solution
summary file
• “Rescaling” / other features can be indexing proteins from
powder diffraction data
Slide 29
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Chekcell GUI indexing helper
Laugier & Bouchu (http://www.ccp14.ac.uk/tutorial/lmgp/)
• GUI Interface
• Reads Crysfire Summary
files and XFIT peak files
• Knows about Spacegroups
• Has Le Page for reduced
cell / sub & super cell
searching
• Automatic best solution
• Automatic best cell
• HKL to peak matching and
optimization of tolerance
Slide 30
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Chekcell - Systematic Absences
and space group possibilities
Laugier & Bouchu (http://www.ccp14.ac.uk/tutorial/lmgp/)
• Scroll down through the
spacegroups
• Graphically see the
effects on allowed lines
• View the absence
condition rules
Slide 31
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Chekcell - Systematic Absences
Scrolling down the spacegroups C2/M (1 of 5)
Slide 32
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Chekcell - Systematic Absences
Scrolling down the spacegroups P2/C (2 of 5)
Slide 33
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Chekcell - Systematic Absences
Scrolling down the spacegroups C2/C (3 of 5)
Slide 34
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Chekcell - Systematic Absences
Scrolling down the spacegroups I2/C (4 of 5)
Slide 35
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Chekcell - Systematic Absences
Scrolling down the spacegroups P21/A (5 of 5)
Slide 36
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Chekcell - Systematic Absences
conditions for P21/A within Chekcell
Slide 37
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
WinGX for Windows single crystal suite
Louis Farrugia: http://www.chem.gla.ac.uk/~louis/software/
• Complete Single Crystal Suite for Windows
• Links to dozens of other programs (new and old)
via GUI interfaces
• Nearly all programs are included with WinGX
distribution
Slide 38
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
WinGX for Windows single crystal suite
Families of programs included/linkable with WinGX
• Importing/viewing data and
models
• Absorption Correction
• Solution (Shelx, difdif, sir, patsee)
• GUI / manual shelxl97 refinement
• Hydrogen addition options
– Shelxl, GUI CalcOH, GUI XHYDEX
• Fourier Contour Map viewing
–
Platon, Contour, Mapview, Marching cubes
• Structure Plotting
• Validation / publishing
Slide 39
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
WinGX for Windows single crystal suite
Absorption Correction
• DREAR - Blessing software
• Numerical
– Gaussian, Analytical, Spherical,
Cylindrical, Needle
• Semi-empirical
– Psi Scans, Camel Jockey,
Multiscan
• DIFABS Style
– Difabs, Xabs, Shelxa
• Interactive Visualisation of
crystal faces using XtalView
Slide 40
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
WinGX for Windows single crystal suite
Structure Solution
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Shelxs97, Shels86, (Shelxd)
Sir97, Sir 92
Dirdif (Patterson and fragment)
Patsee fragment searching
SXGRAPH GUI with WinGX
– SXGRAPH Shelxl GUI allows an
easy interface for loading of
fragments for passing to Patsee or
Dirdif
Slide 41
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
WinGX for Windows single crystal suite
Refinement - Shelxl 97
• GUI control of Shelx via WinGX’s SXGRAPH program
• or Shelx ASCII INS File
Slide 42
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
WinGX for Windows single crystal suite
Hydrogen Addition options
• Shelx97 (G. Sheldrick)
– Manually edit INS file
– Via SXGRAPH GUI
• GUI XHYDEX (G Orphen)
• GUI CalcOH (M Nardelli)
Slide 43
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
WinGX for Windows single crystal suite
Easy Interlinking with Ton Spek’s Platon
• Squeeze/disordered solvent effects
• ADDSYM
• Other Platon Features
Slide 44
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
WinGX for Windows single crystal suite
Fourier Electron Density Contour Maps
• Use LIST 3 command in Shelxl
• Point and click map generation
• View resulting maps in:
– Contour
– Mapview
– Marching Cubes by Michak Husak
Slide 45
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
WinGX for Windows single crystal suite
Structure Plotting
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GUI WinORTEP
GUI WinSTRUPLO
Platon/Pluton/ADP
GRETEP (plugin)
Schakal (plugin)
Rasmol
Photo realistic rendering
– Povray
– Render / RASTER 3D
Slide 46
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
WinGX for Windows single crystal suite
Validation and Structure Checking
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Platon (Addsym, etc)
CIF Validation
Parst
GEOM
THMA 14c
IDEAL
SYMMOL
WTANAL
R-tensor
Slide 47
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Crystals for Windows single crystal suite
David Watkin, Richard Cooper, et al.: http://www.xtl.ox.ac.uk/
• Will focus on Guided
refinement for
teaching purposes
Slide 48
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Guided structure refinement using Crystals
Import Shelx INS file of structure solved by DIRDIF
• Asymmetric unit is
always in view
Slide 49
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Guided structure refinement using Crystals
• Crystals Superviser can
then try and take the
student (user) through the
refinement - giving
guidance where
appropriate
Slide 50
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Guided structure refinement using Crystals
Have now refined atom positions Isotropically
• The Crystals Supervisor
will then make further
recommendations
• (Crystals Scripts means
custom tutorials and
refinement logic can be
added)
Slide 51
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Guided structure refinement using Crystals
Have now refined atom positions anisotropically
• Atoms can be displayed
anisotropically
Slide 52
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Guided structure refinement using Crystals
Automatic Hydrogen Addition
• Graphically compare
calculated hydrogens
(white) to possible
hydrogens found in the
difference map (pink).
Slide 53
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Interrupt the Guided Refinement in Crystals
Manual Hydrogen Addition - 1 of 2
• Crystals explains what is going
on in a language organic
chemists and students can
understand (who may be
learning single crystal methods
as a tool for a larger project) and displayed in organic
chemistry text books.
• May be easier teaching
crystallographic methods to a
specialist audience starting out
with their jargon.
Slide 54
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Interrupt the Guided Refinement in Crystals
Manual Hydrogen Addition - 2 of 2
• A “Wizard” then guides the
user to complete the hydrogen
addition
Slide 55
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Interrupt the Guided Refinement in Crystals
Generating Fourier maps and Marching Cubes for Windows
• Easily generate Fourier
contour maps to show the
electron density. In this
case: electron density due
to the missing hydrogens.
Slide 56
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Guided structure refinement using Crystals
Checking Extinction
• Crystals advises and
guides the user to a
decision on whether
to add extinction in as
a parameter
• A challenge of the
crystallography
teaching course is to
give the background!
Slide 57
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Guided structure refinement using Crystals
Optimize weights
• Crystals advises and
guides the user on
how to optimize the
weights
• Again, a challenge of
the crystallography
teaching course is to
give the reasoning!
Slide 58
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Guided structure refinement using Crystals
Validate Structure
• In this case
validation fails
and crystals
recommends a
course of action
Slide 59
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Guided structure refinement using Crystals
Validation via Cambridge database: geometry checking
• To students and new users, every
structure must seem like a new structure
type. Thus using CSD geometry check
can encourage students to look for errors
or novel features of the structure.
Bondlengths
RED="too long" and BLUE="too short".
RED ---- GREY ---- GREY ---- BLUE
3sigma 2sigma 1sigma 0sigma 1sigma 2sigma 3sigma
Slide 60
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Validation using Crystals
Cambridge database geometry check (1 of 4)
• Doing a CSD check
shows a bond in red
(too long) displaying
a geometry of which
is completely novel
in reference to what
is already known
Slide 61
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Validation using Crystals
Cambridge database geometry check (2 of 4)
• Using the GUI (or
scripts) make the
offending Nitrogen a
Carbon and re-refine.
Slide 62
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Validation using Crystals
Cambridge database geometry check (3 of 4)
• Black bonds around
the renamed atom
tells the user that the
new geometry has
not been tested
against the CSD. So
interrogate the CSD
again to obtain this
information.
Slide 63
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Validation using Crystals
Cambridge database geometry check (4 of 4)
• CSD results now
imply/infer that local
geometry is consistent
with what is already in
the database.
Slide 64
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Validation: Platon for UNIX and Windows
Ton Spek: http://www.cryst.chem.uu.nl/platon/
• Large range of tools
including some life
saving options.
• Will focus on
Addsym for finding
missing symmetry.
Slide 65
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Platon: Validation - Why Bother teaching this?
• For perhaps the same reason that Columbia University
Law/Journalism professors teach their students (at least one - circa late
1940’s):
“If your mother says she loves you,”
“CHECK
IT OUT!!”
• Encourage students to solve, refine and publish structures that can
stand the test of time - that means doing a variety of validation and
using a variety of programs to assist in validation!
Slide 66
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Platon’s Addsym: Structure Published in 1997
P1 - Triclinic: 42 non-H atoms
Slide 67
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Platon’s Addsym: Correction Published in 1999:
C2 - Monoclinic: 22 non-H atoms
Slide 68
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Platon’s Addsym: Press of a button: 2000:
FDD2 - Orthorhombic: 11 non-H atoms
(Short Communication Abstract: "P1 or P-1? Corrigendum", Acta Cryst B56 (2000) 744 from Richard E. Marsh)
Slide 69
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Bonus Personal Rant: Need for the teaching
of competent computer and OS skills!
• Many universities don’t seem to be teaching competent
computer usage and programming skills.
– General computer competence now judged by the ability to use MS
Word and Excel
– HTML taught in computer science departments as it was a
programming language
(instead of more difficult things like Fortran or C)
• Crystallographic teaching courses may have to make up for
lowering standards in student computer competence
Slide 70
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Things to consider: Adding Computer skills
and Programming to teaching courses.
• If the aim is to train employable crystallographers; consider
adding one or two of the following to teaching courses:
– Installing a dual boot UNIX (Linux/FreeBSD) and MS Windows PC;
then compiling/installing crystallographic toolkits as part of a medium
to advanced crystallographic course.
CCP14 based tutorials at:
• Redhat Linux: http://www.ccp14.ac.uk/solution/linux/#install
• FreeBSD: http://www.ccp14.ac.uk/solution/bsdunix/
– Crystallographic programming as part of a rigorous crystallographic
teaching course.
• (Most crystallographic software problems will probably be
technical problems with the PC/? operating system)
Slide 71
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])
Summary
• Advanced freely available software exists that can be useful for
crystallographic teaching if intelligently applied
• This and more software is also mirrored (many with web based
tutorials) via the EPSRC funded CCP14 project and website:
http://www.ccp14.ac.uk
•
(3rd stage funding: August 2001 to August 2006, London, UK)
IUCr Xtal Nexus Software CD-ROM for laboratories / students isolated from the internet:
http://www.unige.ch/crystal/stxnews/nexus/index.htm
(contact Lachlan Cranswick for free copy via air-mail)
• Thanks :
– ACA and session chair
– Professor Dave Walker, Lamont-Doherty Earth Observatory of Columbia
University.
– Apologies: authors of other freely available innovative crystallographic software
for the lack of time in not showing a few dozen more programs
Slide 72
ACA 2001: "Building a teaching course around crystallographic freeware"
Lachlan M. D. Cranswick ([email protected])