Question

8. The monoclinic unit cell is shown below including the angles of the cell. How many atoms below exclusively to the unit cell? Is this primitive or non-primitive? Use the angels as a guide the identify the a, b and c edges on the drawing at left. Please show (draw) the two-fold axis and the mirror plane on the model at right. 222 </ 2 w2

Answer 1

* It is a primitive unit cell * There are 8 atoms in the corner of the unit cell. No other atom is in the cell. So in lattic system each come atom share with 8 other ble lattice cell. So, per atorri contribution = le and there is total se corner. So, exclusively No of atoms present = 8x/ & In lattice system the cell dimensions are 2,6 and e an de intes facial angles are takes as x (angle between b & c) ; B(anale b/w c and a) and & (angle between a and be fict) for a monodinic system of atbtc and 0 == 90° and ß +90 . This unit cell has one two-fold axis and one mirror plane in it. LR two-fold axis of notation pass through the middle of a This is the mirron plane in the the edge lattice