- Get Help
- Getting Started
Welcome to the Help Desk.
This page contains helpful How-to-do pamphlets, Practical materials, Hints and tricks and other suggestions that may make your crystallographic projects a little easier.
Professional Help (all Texas A & M Students, Staff and Faculty)
For Instrument Repair or Usage Questions follow this link >> Instrument Help
Brief Introduction to Single-Crystal Diffraction
SHELX-CARD PDF (SHELXL-97)
SHELX-CARD PDF (SHELXL-2013)
SHELX-CARD EPUB (SHELXL-97)
SHELX-CARD EPUB (SHELXL-2013)
SHELX-CARD MOBI (SHELXL-2013)
JANA page flip manual (Václav Petříček & Michal Dušek)
Our staff is available to assist you with your structure (at any stage). There is no charge for Texas A & M University users, for all other users please contact us for information. Please follow the steps outlined below for assistance.
Step one : Complete the Help Desk Worksheet!
We will require, the full data set, structure information, user information and a brief description of the problem.
Step two : Please compose an e-mail and send this information and the Help Desk Worksheet with the attached data (zipped if necessary).
Step three : We will examine your problem as time permits.
Please E-MAIL us first before your office visit! This will allow us some time to exam your problem and schedule a time to discuss it with you.
Please do not come to our offices WITHOUT the Help Desk Worksheet and the structural information!
Unannounced office visits will not speed up the process and will result in lost time and productivity!
Your problem may require many hours of work so please be patient.
X-ray Diffraction is an analysis tool for solid crystalline, semi-crystalline and amorphous materials. Before you begin you should have a basic understanding of the principles of X-ray Diffraction and Crystallography. There are many good courses available at Texas A & M University and on-line Tutorials (see Tutorials).
- TAMU Users
- Academic Users
- Commercial Users
Two general methods to acquire research information are available to you
1) You may submit a sample to us for investigation
2) You may collect your own data.
If you choose option two then you must first be qualified to use the instrumentation, undertake safety training and go through instrument usage training.
You are qualified to use the instrumentation if you are an employee of Texas A & M University and are covered by workman's compensation insurance.
Visiting researchers are generally covered. Please check with your principle investigator to be sure.
See NEW USERS for full details.
We have been partially funded by the National Science Foundation.
Academic users should submit samples to us in person or by post.
Users are encouraged to follow the steps outlined in the sample submission section of this web site.
CSD for Windows
How to Run Patsee
Powder Data on CCD
start/restart SQL database windows
converting P21/n to P21/c (and back)
Frequently asked questions
is X-ray Diffraction?
Why do you use X-rays?
Why do you use crystals?
How do you determine molecular structure from X-rays and Crystals?
What are crystal lattices and the unit cell?
What are the Bravais Lattices?
What is a Space Group?
Question (for Laboratory users)
How and where to submit samples
To reserve instrument time you must...
How much will it cost?
Do I you need general X-ray safety training YES IF ..
What free crystallographic programs do I need to get started ...
If the X-ray lab collects my data and I want to solve and refine my structure ...
How do I access the Cambridge Data Base?
I need help on solving and/or refining my structure
Odds and Ends
X-rays scatter off of electrons, in a process of absorption and re-admission. Diffraction is the accumulative result of the x-ray scattering of a group of electrons. For an incident X-ray photon of monochromatic wavelength ?, coherent waves are produced at an angle of theta (2-theta with respect to the incident x-ray) if the electron groups interact with the x-ray and are spaced at a distance d. The interaction is described by Bragg's law : nlamda =2dsin(theta). The intensity of the scattered x-ray is proportional to the number of electrons that the x-ray is scattered from.
Normally one would use a microscope to view small objects. For a microscope, light is scattered by an object and collected using lenses, which in turn magnifies the image of the object. The limit of the microscope is intrinsic to the nature of the electromagnetic radiation that is used to probe the object. If we use light we cannot look at objects smaller than the wavelength of light which is about 10 -6 m. Since the atom has dimensions of about 10-10 m we cannot image an atom with a photon of light. X-rays, on the other hand, have a wavelength of about 10 -10 m and are suitable for imaging objects at the atomic scale.
To observe a single object, we normally fix the object to a microscope slide. To view an atom we would need some method to handle a small atom and align it in the microscope. This would be quite difficult and the x-rays scattered by a single atom is extremely week. A better method is to use 1020atoms (the number found in a small -crystal) and to sum the scattered x-rays from each atom. The trick is to align the atoms in neat orderly rows and columns so that the scattered x-rays would form predictable patterns that are based on the original arrangement of the atoms. All of the atoms of a single-crystal are oriented the same way and the scattered x-rays are superimposed and can be measured. Each scattering event that is measures is called a "reflection". There is typically 2000 to 100000 independent reflections for each single-crystal.
The scattered x-rays contain both angular and intensity information. The information concerning the position of the electrons (and atoms) involves both the amplitude and phase of the scattered intensities. For standard data collection techniques the amplitudes for the diffracted intensities are measured, however the phases are lost due to the nature of the experiment. Direct methods is employed to re-determine the phases.
Structure determination is the process of model building, structural factor (intensity) prediction and comparison to the observed structure factors. The model is constructed by introduction of atomic positions at electron density maxima. The model is then employed to predict structural factors which are refined (non-linear least squares) against the observed structural factors. The comparison between the predicted and observed structure factors is known as the residual and attests for the validity of the model.
A single-crystal is described as an order set of atoms (electrons) in a fixed orientation. Typically a single crystal suitable of analysis is at least 50 µm in its smallest dimension and not more than 500 µm in its largest. The smallest non-reproducible volume of the crystal is called the unit cell. The size of the unit cell ranges from a few hundred cubic angstroms (10-10 m) to 10's of thousands. By application of symmetry the unit cell can be repeated, in three dimensions, to describe the entire crystal. The unit cell in turn can be described by three non-coplanar axis a, b and c and the inter axis angles alpha ,beta and gamma which are called the Lattice Parameters. Seven crystal systems are described in terms of the lattice parameters
|SYSTEM||UNIT CELL LENGTH||UNIT CELL ANGLES|
|1) Cubic||a = b = c||alpha=beta=gamma=90deg|
|2) Tetragonal||a = b||alpha=beta=gamma=90deg|
|3) Orthorhombic||no conditions||alpha=beta=gamma=90deg|
|4) Rhombohedral||a = b = c||alpha=beta=gamma does not equal 90deg|
|5) Hexagonal||a = b||alpha=beta=90deg gamma=120deg|
|6) Monoclinic||no conditions||alpha=beta=90 deg|
|7) Triclinic||no conditions||no conditions|
|2) (single face centered cells)|
|A face (bc plane) - centered||A|
|B face (ac plane) - centered||B|
|C face (ab plane) - centered||C|
|3) Face - centered||F|
|4) Body - centered||I|
Space groups are a way of describing how objects are arranged in three-dimensional space. There are four symmetry operations allowed in three dimensional "space".
|Operation||Symbol (Hermann)||Symbol (Schoenflies)|
|Rotation||1,2,3,4,6||E, C2, C3, C4, C6|
A symmetry operation followed by translation is also allowed
Screw axis 21, 31, 32, 41, 43, 61, 65
Glide planes a,b,c,n,d
A space group is described as a closed set of symmetry operations that describe the total symmetry of a given volume of space (unit cell). The first letter of the space group describes the centered cell (P, A, B, C, F or I). The following symbols represent the smallest set of non-reducible symmetry operations.
e.g. Pmmm Primitive cell with three perpendicular mirror planes
Submit your samples to the X-ray staff for approval. Bring your sample to rm 2409 between 9:00am-5:00pm weekdays
There are two ways to submit your sample and determine your structure.
1st ) You can request that the x-ray diffraction laboratory staff undertake the investigation.
This way is suggested if ...
a) you undertake only a few structural determinations a year
b) your advisor does not want you to undertake the time and expense of learning a new skill.
2nd ) You can be trained and you can do your own work. This method is suggested if ...
a) your structures are major part of your research
b) you must defend your structures before skeptical investigators
If you choose for the x-ray diffraction laboratory staff to do your structure or powder diffraction experiment then we will reserve time for you. If not you should reserve time on one of the three CCD diffractometers, the GADDS diffractometer, the D8 discover, the D8 vario or the SAXS instrument
To reserve time please use the calendar reservation system.
See the x-ray diffraction facility manager for the SAXS reservation.
See Fees. For Industrial users please call 979-845-9125 or e-mail.
For Industrial users please call 979-845-9125 or e-mail.
Yes !! : If you intend to do your own structures
No : If you wish for the staff to do your structures
X-ray Safety Training
Before you begin the x-ray staff will train you on the site specific safety issues.
Goto NEW USERS page for further details.
For more general x-ray safety training you will be expected to attend one of the classes presented by the Environmental Health and Safety Department (EHSD). Their training schedule can be found here : General X-ray Training
You should download some of the free crystallographic software on the net
a)WinGX - A GUI (windows) for some of the most popular (and free) software. First download the software and then e-mail the author for a free license. SHELXS, SHELXL, PLATON, SIR92 and several other valuable programs come with the package.
b)GTREP - A structure graphics and plotting program. Will plot thermal ellipsoids.
C)Mercury from the CSD
You will be given (at least) two files project_name.HKL and project_name.INS with these files and WinGX you can solve refine and display your structure. The X-ray Staff will assist you the first few times.
The Cambridge Crystallographic Data Base is located on a PC computer RedHat Linux E5 (xray.chem.tamu.edu) and can be accessed by here
You can get help with your structure. Goto the Helk Desk on this site
Crystals : See Growing Crystals
P.G. Jones: Crystal growing, Chemistry in Britain (1981) 17, 222-225.
J. Hulliger: Chemistry and Crystal Growth, Angew. Chem. Int. Ed. Engl. (1994) 33, 143-162. Angew. Chem. (1994) 106, 151-171.
A. Holden, P. Morrison: Crystals and Crystal Growing, MIT Press, Cambridge, Massachusetts (1982) ISBN 0-262-58050-0
J.W. Mullin: Crystallization, Butterworth-Heinemann, Oxford, Great Britain (1993) ISBN 0-7506-1129-4
I mount my sample?
Two methods are commonly employed.
a)Thin glass fiber
A thin glass fiber is pulled and attached to a copper pin (magnetic base, Hampton) with clay and finger nail polish. The fiber can be pulled by heating a Klimax® melting point tube in a hot flame. The fiber is typically 50 to 100 mm in diameter. The crystal is glued to the fiber with an adhesive.
A thin (thickness = 20mm) 0.7 mm diameter nylon loop (Hampton) that is attached to a magnetic base is coated with Paratone® or Apieazon® grease is used to "lasso" (Texas style) a crystal and pulled it off the microscope plate.
-Crystals can be covered with a thin layer of oil to prevent decomposition in air.
Paratone® (a poly-isobutylene: additive free STP)
Poly-isobutylene (is available in several viscosities)
Perfluorinated oils (Krytox® oil)
Epoxy resin (less hardener)
-If your crystals lose solvent, try adding a few drops of the solvent (mother liquor) to mineral oil or paratone and then cover the crystals with this mixture. Some experimentation on solvent concentrations in the oil may be needed.
-Adhesives for specimen pins
super glue holds up to 373K dries fast
dental cemen to 573K dheres to glass well
Epoxy resins to 373K slow drying
Apiezon® Grease(T) to 103K slow scatter
Silicon Grease (not 4) to 133K Si scatter (cheap)
Vaseline to 200K sticky
Balsam to RT dilute with xylene)
Wax to RT permanent
Birth of Crystallography :
1669 Nicolaus Skno : Determined that angles between crystal faces remained constant between crystals of the same compound.
1895 Rontgen :
Discovers X-rays : Science (1896) 53, 274. (in English)
First X-ray Diffraction Experiment : Friedrick, W. Knipping, P. & Laue, M. Bravarian Acad. Sci. (1912) 303.
First Structure Determination : Bragg, W.H & Bragg W.L. Proc. Royal. Soc. (1913) A88, 428.
First X-ray Camera (Powder): Debye, P. & Scherrer, P. Phys Z. (1916) 17, 277-283.
Hull, A. W. Phys. Rev. (1917) 10, 661-696.
First X-ray Diffraction Instrument: Weissenberg, K. Z.Phys. (1924) 23, 229.
First Geiger Counter: Locher, G.L. & LeGalley, D.P. Phys. Rev. (1933) 46, 1047.
First X-ray Precession Instrument : Buerger, M.J. "X-ray Crystallography" (1942) Wiley, New York
First Scintillation Counter: West, H.I., Mayerhot, W.E., Hotstadter, R. Phys. Rev. (1951) 81, 141.
1. Crystal structure determination by: Werner Massa
"My favorite introduction to Crystallography"
"It's the one book I would force into a student hands!"
2. Crystal Structure Analysis by: Glusker and Trueblood
"A good starter for the common scientist"
3. Crystal Structure Determination and Crystal Structure Analysis by: Bill Clegg
"One of my favourite and informative book(s). First time crystallographers should read these books first."
4. Cystallography Made Crystal Clear by: Gale Rhodes
"For the Novice/macromolecular user"
5. Fundamentals of Powder Diffraction and Structural Characterization of Materials by: Pecharsky and Zavalij
"Only book that I know of that explains indexing and indexing programs"
"A must own book for the powder and single-crystal diffractionist!"
"A gota-have book for people interested in the bigger picture"
6. Structure Determination by X-ray Crystallography by: Ladd and Palmer
"I have given Ladd and Palmer to non-crystallographers who needed to gain
a basic understanding of the process."
7. X-ray Structure Determination by: Stout and Jensen
"a good, practical book for the student after they are into the subject"
8. X-ray Analysis and the Structure of Organic Molecules by: Dunitz
"a great book (even for an inorganic chemist) and it is filled Jack's usual wit"
"The section on weighting schemes in least squares is a must read"
9. The Determination of Crystals Structures by: Lipson & Cochran
"It is still an amazing book!"
10. Fundamentals of Crystallography edited by C. Giacovazzo
"A MUST HAVE for a lab"
"For more advanced students Giacovazzo is a must."
Jones, P.G. (1986) Acta Cryst.A42, 57-57.
H.D. Flack (1983) Acta Cryst.A39, 876-881
G. Bernardinelli and H.D. Flack (1985) Acta Cryst.A41, 500-511.
H.D. Flack and G. Bernardinelli (2000) J. Appl. Cryst. 33, 1143-1148.
Rogers absolute structure
Rogers D. (1981) Acta Cryst.A37 734-741.
Jones P.G. (1984) Acta Cryst.A40, 660-662.
Hamilton, W.C. (1965) Acta Cryst.18, 502-510.
Alternative to Hamitons' R-test
Rothstein, S.M. ; Richardson, M.F. and Bell, W.D. (1978) Acta Cryst.A34, 969-974
International Tables for Crystallography, Volume C (1992), Ed. A.J.C. Wilson, Kluwer Academic Publishers, Dordrecht: 220.127.116.11 (pp. 193-199).
Blessing, R.H. (1995) Acta Cryst. A51, 33-38.
Azimuthal only (no theta dependence)
North A.C., Philips, D.C. and Mathews, F. (1968) Acta Cryst .A24, 350-359.
Azimuthal + theta correction
Flack, H.D. (1974) Acta Cryst. A30, 569-573.
DeMeulenaer, J. and Tompa, H. (1965) Acta Cryst. 19, 1014-1018.
Katayama, C. (1986) Acta Cryst. A42, 19-23.
Busing, W.R. and Levy, H.A. (1957) Acta Cryst. 10, 180-182.
Coppens, P., Leiserowitz, L. and Rabinovich, D. (1965) Acta Cryst. 18, 1035-1038.
Katayama, C. (1972) Acta Cryst. A28, 293-295.
Walker, N. and Straurt, D. (1983) Acta Cryst. A39 158-166.
Parkin, S.; Moezzi,B. and Hope, H. (1995) J.Appl.Cryst. 28, 53-56.
International Tables for X-ray Crystallography, Vol II. Birmingham; Kynoch Press., Tables 5.3.6B pages 302-305.
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Tests for Center of Symmetry
Wilson, A.J.C. (1949) Acta
Cryst., 2, 318-321.
Howells, E.R.; Phillips, D.C. & Rogers D. (1950) Acta Cryst., 3, 210-214.
Marsh, R.E. (1986) Acta Cryst., B42, 193-198.
Crystallographic Information File
CIF format :: I.U.Cr.
Commission on Crystallographic Data:
S.R. Hall, F.H. Allen and I.D. Brown (1991) Acta Cryst., A47, 655-685.
Ipso-angles of phenyl rings differ systematically from 120 degrees
P.G. Jones (1988) J. Organomet. Chem., 345, 405
T. Maetzke and D. Seebach (1989) Helv. Chim. Acta, 72, 624-630
A. Domenicano, "Accurate Molecular Structures", eds. Domenicano and Hargittai, Chapter 18, OUP (1992)
Standard (restraint) bond lengths based on the CSD
F.H.Allen, O. Kennard, D.G. Watson, L. Brammer, A.G. Orpen and R. Taylor in Sections 9.5 and 9.6 of Volume C of "International Tables for Crystallography" (1992), Ed. A.J.C. Wilson, Kluwer Academic Publishers, Dordrecht, pp. 685- 791.
Standard (retraint) bond lengths for protiens
R.A. Engh and R. Huber (1991) Acta Cryst., A47, 392-400.
Standard (restraint) bond lengths For nucleic acids
R. Taylor and O. Kennard (1982) J. Mol. Struct., 78, 1-28 (bases and phosphates)
S. Arnott and D.W.L. Hukins (1972) Biochem. J., 130, 453-465 (furanose rings).
Plainarity of nucleic acid bases
R. Taylor and O. Kennard (1982) J. Am. Chem. Soc., 104, 3209-3212
Diffuse solvent modeling by Babinet's principle
R. Langridge, D.A. Marvin, W.E. Seeds, H.R. Wilson, C.W. Hooper, M.H.F. Wilkins and L.D. Hamilton (1960) J. Mol. Biol., 2, 38-64
H. Driessen, M.I.J. Haneef, G.W. Harris, B. Howlin, G. Khan and D.S. Moss, J. (1989) J. Appl. Cryst., 22, 510-516
Rigid body analysis
Schomaker, V. and Trueblood, K.N. (1968) Acta Cryst., B24, 63-76.
Data Collection and Reduction
Area Detection -CCD
S. Ruhl and M. Bolte (2000) 215, 499-509
Area Detection -peak bases
Bolotovsky, R.; White, M.A.; Darovsky, A. and Coppens, P. (1995), J. Appl. Cryst. 28, 86-95.
Alexander, L & Gordon S.S. (1962) Acta Cryst., 15, 983-1004.
Samson, S. and Schuelke, W.W. (1967) Rev. Sci. Instr., 38, 1273-1283.
Cell reduction and Lattice Symmetry
Glegg, W. (1981) Acta Cryst., A37, 913-915.
Gruber, B. (1973) Acta Cryst., A29, 433-440.
Scan type Wyckoff
Wyckoff, H.W.; Doscher, M.; Tsernoglou, D.; Inagami, T.; Johnson, L.; Hardman, K.D.; Allewell, N.M.; Kelly,M. & Richards, F. (1967) J. Mol. Biol., 27, 563-578.
Blessing, R.H. (1987) Cryst. Rev., 1, 3-58.
Blessing, R.H. & Langs, D.A. (1987) J.Appl. Cryst., 20, 427-428.
X-ray beam and Detection
Harkema, S.; Dam, J.; Van Hummel, G.J. and Reuvers, A.J. (1980) Acta Cryst., A36, 433-435.
Katrusiak, A. & Ryan, T.W. (1988) Acta Cryst., A44, 623-627.
Nelson, J.T. & Ellickson, R.T. (1955) J. Am. Opt. Soc., 45, 984-986.
Slaughter, M. (1968) Kristallogr., 129, 24-35.
McCanlish, L.E.; Stour. G.H. and Andrews, L.C. (1975) Acta Cryst., A31, 245-249.
French, S. & Wilson, K. (1978) Acta Cryst., A34, 517-525.
Learnt Profile Analysis
Diamond, R. (1969) Acta Cryst., A25, 43-55.
Clegg, W. (1981) Acta Cryst., A37, 22-28.
Lehmann, M.S. & Larsen, F.K. (1974) Acta Cryst., A30, 580-584.
Reibenspies, J.H. (1994) J.Appl.Cryst. 26,426-430.
Tickle, I.J. (1975) Acta Cryst. B31, 329-331.
Slope Detection method
Grant, D.F. & Gabe, E.J. (1978) J.Appl. Cryst. 11, 114-120.
Misc. procedures and investigations
Spencer S.A. and Kossiakoff (1980) J. Appl. Cryst., 13, 563-571.
Dudka, A.P. and Loshmanov, A.A. (1992) Sov. Phys. Crystallogr., 36, 625-626.
Langford, J.L. (1978) J. Appl. Cryst., 11, 10-14.
Lehmann, M.S. (1975) J. Appl. Cryst., 8, 619-622.
Chulichkov, A.I.; Chulichkova, M.; Fetisov, G.; Pyt'ev,Y.P.; Lupyan, Y.V.;Laltionov, A.V.; Nesterenko, A.P. and Aslanov, L.A. (1987) Sov. Phys. Crystallogr., 32, 649-653.
van der Wal, H.R.; de Boer, J.L. and Vos, A. (1979) Acta Cryst., A35, 685-688.
Strel'tsov, V.A. and Zavodnik, V.E. (1989) Sov. Phys. Crystallogr., 34, 824-828.
Norrestam, R. (1972) Acta Chem. Scand., 26, 13-21.
Rigoult, P. J. (1979) J.Appl.Cryst., 12, 116-118.
Blessing, R.H.; Coppens, P. & Beker, P. (1972) J. Appl. Cryst., 7, 488-492.
Rossman, M.G. (1979) J. Appl. Cryst., 12, 255-238.
Reflection Intensity Photography
Xuong, N. & Freer S. Acta Cryst., B27, 2380-2387.
Laue Film Integration & Deconvolution
Shrive, A.K.; Clifton,I.J.; Hajdu, J. and Greenhough T.J. (1990) J. Appl. Cryst., 23, 169-174.
Abrahams, S.C. and Marsh, P. (1987) Acta Cryst., A43, 265-269.
Ibers, J.A. (1969) Acta Cryst., B25, 1667-1668.
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A.C. Larson in "Crystallographic Computing" (1970), Ed. F.R. Ahmed, Munksgaard, Copenhagen, pp. 291-294.
Larson, A.C. (1967) Acta Cryst., 23, 664-665.
Zachariasen, W.H. (1963) Acta Cryst., 16, 1139-1144.
Least Squares Refinement
Floating origin restraints:
H.D. Flack and D. Schwarzenbach (1988) Acta Cryst., A44 499-506.
Use of all data in refinement.
F. L. Hirshfeld and D. Rabinovich (1973) Acta Cryst., A29, 510-513
L. Arnberg, S. Hovmoller and S. Westman (1979) Acta Cryst., A35, 497-499
Refinement of racemic twins
Pratt, Coyle and Ibers (1971) J. Chem. Soc., 2146-2151
Jameson (1982) Acta Cryst., A38, 817-820.
Conjugated Gradient L. S. algorithm
W.A. Hendrickson and J.H. Konnert "Computing in Crystallography", Ed. R. Diamond, S. Ramaseshan and K. Venkatesan, I.U.Cr. and Indian Academy of Sciences, Bangalore 1980, pp. 13.01-13.25.
D.E. Tronrud (1992) Acta Cryst., A48, 912-916.
Least-Squares Restraints :
J.S. Rollett in "Crystallographic Computing", Ed. F.R. Ahmed, S.R. Hall and C.P. Huber, Munksgaard, Copenhagen, (1970) pp. 167-181.
F.L. Hirshfeld (1976) Acta Cryst., A32, 239-244
K.N. Trueblood and J.D. Dunitz (1983) Acta Cryst., B39,120-133.
.J. Didisheim and D. Schwarzenbach (1987) Acta Cryst., A43, 226-232
Shift limiting least-squares restraints (damping) Marquardt algorithm ::
Marquardt (1963) J. Soc. Ind. Appl. Math., 11, 431-441.
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Sheldrick, G. (1990) SHELXTL-PLUS revision 4.11V, SHELXTL-PLUS users manual,Siemens Analytical X-ray Inst. Inc., Madison WI, U.S.A.
Sheldrick, G. (1986) SHELXS-86 Program for Crystal Structure Solution, Institüt für Anorganische Chemie der Universität, Tammanstrasse 4, D-3400 Gottingen, Germany.
Sheldrick, G. (1997) SHELXL-97 Program for Crystal Structure Refinement, Institüt für Anorganische Chemie der Universität, Tammanstrasse 4, D-3400 Gottingen, Germany.
teXsan : Single Crystal Structure Analysis Software, Version 1.6 (1993). Molecular Structure Corporation, The Woodlands, Texas 77381.
Beurskens, P., Admiraal, G., Beurskens G., Bosman, S., Garicia-Granda, R., Gould, J., Smykalla, A. and Smykalla, C. (1992). DIRDIF-99 program system, Technical Report of the Crystallography Laboratory, University of Nijmegen, The Netherlands
Giacovazzo C. (1997) SIR-97 Program for Crystal Structure Solution, Inst. di Ric. per lo Sviluppo di Metodologie Cristallograpfiche, CNR, Univ. of Bari, Italy.
SIR88 : Burla, M.C.; Camalli, M.; Ccascarano, G.; Giacovazzo, C.; Polidori, G. and Viterbo, D. (1989) J. Appl. Cryst. 22, 389-393.
Egert, E. (1985) PATSEE Program for Crystal Structure Solution by Integrated Patterson and Direct Methods, Institüt für Anorganische Chemie der Universität, Tammanstrasse 4, D-3400 Gottingen, Germany. Egert, E. and Sheldrick, G. (1985) Acta Cryst A41, 262-268.
SCHAKAL88 : Keller, E. (1989) J. Appl. Cryst. 22, 12-22.
Spek, A.L.. (2002) PLUTON. Program for Molecular and Crystal Graphics. Vakgroep Algemene Chemie, University of Utrecht, Afdeling Kristal-En Structuurchemie, Padualaan 8, 3584 Ch Utrecht, The Netherlands.
Spek, A.L.. (2002) PLATON. Program for Crystal Structure Results Analysis. Vakgroep Algemene Chemie, University of Utrecht, Afdeling Kristal-En Structuurchemie, Padualaan 8, 3584 Ch Utrecht, The Netherlands.
Johnson, C.K. (1976) ORTEP-II. A Fortran Thermal-Ellipsoid Program, Report ORNL-5138. Oak Ridge National Laboratory, Oak Ridge Tennessee.
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groups/ Laue symmetry / Unit cell
polar space groups
H.D. Flack and D. Schwarzenbach (1988) Acta Cryst., A44 499-506
LePage, Y. (1987) J Appl. Cryst., 20, 264-269
Lattice symmetry determination
Mighell, A.D. and Rodgers, J.R. (1980) Acta Cryst., A36, 321-326.
Baur, W.H. and Tilmanns, E. (1986) Acta Cryst., B42, 95-111.
Structure inversion for special space groups
E. Parthe and L.M. Gelato (1984) Acta Cryst., A40, 169-183
G. Bernardinelli and H.D. Flack (1985) Acta Cryst., A41, 500-511
Statistical Descriptors in Crystallography
D. Schwarzenbach; Abrahams, S.C.; Flack, H.D.; Gonschorek, W.; Hahn, T;Huml, K.; Marsh, R.E.; Prince, E.; Robertson, B.E.; Rollet, J.S. and Wilson, A.J.C. (1989) Acta Cryst., A45, 63-75.
H.D. Flack (1983) Acta Cryst., A39, 876-881.
Twinning structural reasons.
W. Hoenle and H.G. von Schnering (1988) Z. Krist., 184, 301-305.
Buerger, M.J. (1945) J. Am. Miner., 30, 469-482.
R. Herbst-Irmer, G. Sheldrick (1998) Acta Cryst, B54, 443-449.
A.J.C. Wilson (1976) Acta Cryst., A32, 994-996.
J.D. Dunitz and P. Seiler (1973) Acta Cryst., B29, 589-595.
Honkimaki, V.; Sleight, J. and Suorott, P. (1990) J. Appl. Cryst., 23, 412-417.
Tools of the Trade
User Manuals (all are freely avialable on the web)
apexii user manual 2010
RADIATION SAFETYTRAINING GUIDE 441-1-12
REGULATORY GUIDE 08-029
ShelX - Guide (Gregory S. Girolami, Julia L. Brumaghim, James G. Priepot, and Jon P. Goveia)
William Clegg and David G. Watson (2008) Acta Cryst. E64, e15-e17.
Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan.
APEX, APEX2, SMART, SAINT, SAINT-Plus:
Bruker (2007). Program name(s). Bruker AXS Inc., Madison, Wisconsin, USA. [Older versions (pre-1997) should refer to SiemensAnalytical X-ray Instruments Inc. instead of Bruker AXS.]
Enraf–Nonius (1989). CAD-4 Software (or CAD-4 EXPRESS). Enraf–Nonius, Delft, The Netherlands.
Cambridge Structural Database:
Allen, F. R. (2002). Acta Cryst. B58, 380–388.
Watkin, D. J., Prout, C. K. & Pearce, L. J. (1996). CAMERON.Chemical Crystallography Laboratory, Oxford, England.
CrysAlis CCD, CrysAlis RED and associated programs:
Oxford Diffraction (2006). Program name(s). Oxford Diffraction Ltd,Abingdon, England.
Betteridge, P. W., Carruthers, J. R., Cooper, R. I., Prout, K. & Watkin,D. J. (2003). J. Appl. Cryst. 36, 1487.
Nonius [or Hooft, R.W.W.] (1998). COLLECT. Nonius BV, Delft, The Netherlands.
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press.
Brandenburg, K. [or Brandenburg, K. & Putz, H., or Brandenburg, K.& Berndt, M.] (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.
DIF4 and REDU4:
Stoe & Cie (1991). Program name(s). Stoe & Cie, Darmstadt, Germany.DIRAX:
Duisenberg, A. J. M. (1992). J. Appl. Cryst. 25, 92–96.
Allen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M.(2004). J. Appl. Cryst. 37, 335–338.
Duisenberg, A. J. M., Kroon-Batenburg, L. M. J. & Schreurs, A. M. M.(2003). J. Appl. Cryst. 36, 220–229.
Petrˇıcˇek, V. & Dusˇek, M. (2000). JANA2000. Institute of Physics, CzechAcademy of Sciences, Prague, Czech Republic.
Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P.,Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39,453–457.
Bruno, I. J., Cole, J. C., Kessler,M., Luo, J., Motherwell,W. D. S., Purkis,L. H., Smith, B. R., Taylor, R., Cooper, R. I., Harris, S. E. & Orpen, A. G. (2004). J. Chem. Inf. Comput. Sci. 44, 2133–2144.
Johnson, C. K. (1976). ORTEPII. Report ORNL-5138. Oak RidgeNational Laboratory, Tennessee, USA.
Burnett, M. N. & Johnson, C. K. (1996). ORTEPIII. Report ORNL- 6895. Oak Ridge National Laboratory, Tennessee, USA.
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
Nardelli, M. (1995). J. Appl. Cryst. 28, 659.
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13.
Rigaku (1996). PROCESS. Rigaku Corporation, Tokyo, Japan.
Rigaku (1998). PROCESS-AUTO. Rigaku Corporation, Tokyo, Japan.
Westrip, S. P. (2008). publCIF. In preparation.
Bruker (2001). Program name. Bruker AXS Inc., Madison, Wisconsin,USA.
Sheldrick, G. M. (1996). Program name. University of Go¨ ttingen,Germany.
All programs beginning with SHELX:
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla,M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435.
Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo,C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999).J. Appl. Cryst. 32, 115–119.
Burla, M. C., Camalli, M., Carrozzini, B., Cascarano, G. L., Giacovazzo, C., Polidori, G. & Spagna, R. (2003). J. Appl. Cryst. 36, 1103.
Molecular Structure Corporation & Rigaku (2000). TEXSAN. MSC, The Woodlands, Texas, USA, and Rigaku Corporation, Tokyo, Japan.
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.
X-AREA, X-RED, X-RED32, X-SHAPE:
Stoe & Cie (2002). Program name(s). Stoe & Cie, Darmstadt, Germany.
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.
Siemens (1994). XSCANS. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189–191
Crystallographic Databases available for TAMU domain users.
- Cambridge CSD
- Inorganic ICSD
- Powder ICDD
- Misc. Databases
The Cambridge Crystallographic Data Base is available on line see WebCSD.
A copy is also located on a windows computer in room 2409.
The Inorganic Crystal Structure Database
The icsd data base is available on-line see ICSD
You must enter the data base from the .tamu.edu domai
The International Centre for Diffraction Data
Powder Diffraction database.
The Department of Chemistry presently owns the 2004 license. This is restricted to data base searches with the program EVA.
See the database manager for details.