chem5410 q1 2/20 & 2/27/’06

Chem5410 Q1 2/20 & 2/27/’06

1. What is so-called a single-crystal?

2. What is so-called a powder sample?

3. Does a powder sample contain single crystals?

4. What’s the difference between single-crystal diffraction and powder diffraction?

5. What is Bragg Law? And what’s the use of it in structure analysis ?

6. In diffraction experiments, what’s the X-ray wavelength used in SXRD? And what’s the X-ray wavelength used in PXRD?

7. What is the suitable size of single crystal for SXRD measurements?

8. How X-rays are generated?

Chem5410 Q2 2/27 & 3/06/’06

1. What are so-called cell constants? How many should be determined?

2. What are so-called the external symmetry of a crystal?

3. What are so-called the internal symmetry of a crystal?

4. What point symmetry groups are possessed by crystals?

5. What is so-called a space group?

6. How to define crystal planes?

7. What’s relationship between lattice planes and cell constants?

8. What’s the so-called the seven crystal

Chem5410 Q3 3/06/’06

1. What are so-called structure Factors?

2. What are so-called lattice types?

3. What are so-called the 14 Bravais lattices?

4. How to determine the cell constants for a crystalline sample?

5. How to determine the correct unit cell for a crystalline sample?

6. How to determine the correct point group for a crystal lattice?

7. What’s the relationship between crystal lattice and diffraction pattern?

8. Why XRD patterns exhibit symmetries?

N2A

C2A

O1B

O3N2

C1A

C2

ZN1

O3

O3C

N1

O1A

N2B

C1

P2

C1B

O1C

O3B

C2B

P1

O4

O1

O2

O5

ab

c

ORTEP for ZnP1