Crystallography matters ... more!

Venue: University Marien Ngouabi, Brazzaville, Republic of Congo Date: 18-28 May 2020 11-22 May 2022

Click here to read the official communiqué (in French) by Joseph Marie MOUTOU, Chair of the LOC.

>> Read a report of the IUCr-UNESCO OpenLab Congo-Brazzaville in the IUCr Newsletter <<

The IUCr-UNESCO OpenLab Congo-Brazzaville is organised as part of the activities of the Association Congolaise de Cristallographie (ACCr) in collaboration with the University Marien Ngouabi and the Geological and Mining Research Centre (CRGM).

X-ray diffraction data for use at the OpenLab will be collected at the University of Lorraine, Nancy, France. 

Organizing Committee

Local Organizing Committee

President: Joseph Marie MOUTOU, Maître de Conférences, University Marien Ngouabi, Congo
1st Vice-president: Joachim MANDAVO, Maître-Assistant, University Marien Ngouabi, Congo
2nd Vice-président: Ferland NGORO-ELENGA, Assistant, University Marien Ngouabi, CRGM, Congo
Secretary: Patrick Rodeck LOEMBA, CETP, Marien NgouabiUniversity, Congo
Treasurer: Maryse Caroline ITOUA, Reseacher, CRGM, Congo
Members:
Hubert MAKOMO, Maître-Assistant, University Marien Ngouabi, Congo
Laurent MATINI, Maître de Conférences, University Marien Ngouabi, Congo
Antoine FILANKEMBO, Maître-Assistant, University Marien Ngouabi, Congo
Alain Second DZABANA, Assistant, University Marien Ngouabi, Congo

International Organizing Committee

President: Claude LECOMTE, Professor Emeritus, Chairman of IUCr Africa Initiative, Université de Lorraine – Nancy, CRM2, CNRS, France
1st Vice-président: Hilaire ELENGA, Maître de Conférences, Marien NGOUABI University, CRGM, Congo
2nd Vice-président: Patrice KENFACK TSOBNANG, Senior Lecturer and Researcher, University of Dschang, Secretary of African Crystallographic Association (AfCA), Cameroon.
Members:
Timothée NSONGO, Professeur Titulaire, Marien NGOUABI University, CRGM, Congo
Florence PORCHER, Engineer-researcher, Université de Lorraine – Nancy, CEA, France
El Eulmi BENDEIF / Emmanuel WENGER, Université de Lorraine – Nancy, CRM2, France

Lecturers/Trainers

Claude Lecomte, Université de Lorraine, Nancy, France
Patrice Kenfack Tsobnang, Université de Dschang, Cameroon
Florence Porcher, Université de Lorraine, Nancy and CEA, Saclay, France
El Eulmi Bendeif, Université de Lorraine, Nancy, France
Emmanuel Wenger, Université de Lorraine, Nancy, France 

Topics

Programme

First week
Monday
09:00-09:45 Crystallography: indispensable domain of science at the interface of physics, chemistry, geology, and health science (CL)
09:45-10:30 Crystal lattice: definitions and calculations part 1 (CL)
10:30-11:00 coffee break
11:00-12:15 Crystal lattice: definitions et calculations part 2; isométry (CL)
12:15-14:15 meal
14:15-16:15 Exercises of crystallographic calculation: 3 groups de 12-15 étudiants: (FP, PK, EW, EB, CL)
16:15-16:45 coffee break
16:45-18:15 X-ray scattering by matter (CL)
18:15-19:00 Diffractometer: laboratory X-ray production and introduction to synchroton radiation (EW or EB)

Tuesday
09:00-10:30 X-ray diffraction by crystals part 1 (CL)
10:30-11:00 coffee break
11:00-12:15 X-ray diffraction by crystals part 2 (CL)
12:15-14:15 meal
14:15-16:15 Powder and single crystal diffractometers: goniometer and X-ray detector (EW or FP)
16:15-16:45 coffee break
16:45-19:00 Exercises: crystallographic calculations, isometry (FP and PK, EW, EB and CL)

Wednesday
09:00-10:30 Point symmetry, point symmetry group (CL)
10:30-11:00 coffee break
11:00-12:15 Exercises: representative matrices, point group stereographic projection
(FP or PK, EW, EB and CL)
12:15-14:15 meal
14:15-16:00 Space group symmetry (CL)
16:00-16:30 coffee break
16:30-19:00 International Tables for Crystallography : introduction and exercises (FP and PK, EW, EB and CL)

Thursday
09:00-10:30 X-ray diffraction part 3 (CL)
10:30-11:00 coffee break
11:00-12:15 X-ray diffraction exercises (structure factor calculation, space-groups determination (FP and PK, EW, EB and CL)
12:15-14:15 meal
Two groups of 25 person will be formed
- Group A: diffraction by single crystal (EW or EB)
- Group B: diffraction by powders (FP, PK)
14:15-16:15 Practical aspects
Group A: general presentation of X-ray diffraction par single crystal and Bruker D8 diffractometer (EW or EB)
Group B: general presentation of X-ray diffraction by powders and Bruker D2 diffractometer (FP)
16:15-16:45 coffee break
16:30-18:30
Group A: Single crystal diffractometer: Introduction (EW or EB, CL)
Group B: Diffraction des rayons X par les poudres : Introduction FP

Friday
Practical aspects:
Group A: Diffraction on single crystal (CL, EB or EW)
09:00-10:30 Choice of crystal, preparation of data collection software
10:30-11:00 coffee break
11:00-12:15 Get the squares of the structure factors: data reduction, software presentation
12:15-14:15 meal
14:15-19:00 Data processing performed at Dschang on a bruker single crystal diffractometer
Group B: diffraction on powders (FP)
09:00-10:30 Samples preparation, measurement parameter and processing software – Measurement of diffractograms on the D2 Bruker diffractometer
10:30-11:00 coffee break
11:00-12:15 Diffractogram analysis : indexation, metric and phase identification. Measurement of diffractograms (continuation).
12:15-14:15 meal
14:15-19:00 Diffractogram analysis : peak intensity, refinement of crystal sctructures by Rietveld method. Measurement of diffractogram (continuation).

Second week
Monday
09:00-11:30 Least squares refinement methods : theory and applications
12:15-14:15 meal
14:15-16:30 Presentation of data interpretation software and structure resolution
Group A: Apex3, Shelx, Mercury, Ortep, WingX , Olex2 (EB or EW , CL)
Group B: FullProf suite, Topas (FP and PK)
16:00-16:30 coffee break
17:00-19:00 PRACTICAL USE OF SOFTWARE (EB, FP, PK)

Tuesday and Wednesday
Days consacrated to measurements, use of software et interpretation
Groups A and B
- Single crystal diffractometer (group A) : (EB or EW)
- Conditions and measurement strategies
- Critical analysis of the first results
- Generation of different files and structural data tables
- Redaction of the experimental part of a scientific publication
- Redaction of description of the crystal structure
- Powder diffractometer (group B) (FP and PK)

Thursday
Morning devoted to databases
09:00-12:15 Course: introduction to structural databases and use: CCDC, COD 1h30 PK et 1h30 FP.
12:15-14:15 meal
14:15-17:15
- Critical reading of publications on structural analysis from X-ray diffraction data on single crystal and powders.
- Critical analysis of the crystallographic results presented in these publications : what is the basic information to include in a crystallographic article ?
17:30 Openlab balance sheet, future and graduation ceremony.