You will be presented with three crystallographic directions drawn in a unit cell. Please write the identity of the direction in the space provided below each picture. Use the correct form of brackets for describing a direction, and leave no spaces between numbers. If you must use a negative sign you should write a negative sign directly before the negative number. Again, use no spaces. Ex: (83-8) would be the 8, 3, -8 plane

i don't know whats wrong with my answers in this question. it ask for the directions i.e. the vector (xyz) so the first crystal has vector pointing down one unit for the z value i.e. -1. and x is 1/3, whereas y is 0 so i gave (1/30-1) and got it wrong with the others...

According to Miller Index we express the vector as a set of whole numbers, so I multiply through by 3. So, I've tried the crystallographic direction of the red vector as(10-3), but it's still wrong...

Same here. i tried twice bt still m wrong

just try it this way. i am sure u will get it. 1st of all they are vectors which are given for which you need to give direction. They are not asking planes. So u need to use square brackets [ and ] not ( and ). Those are for planes. 2nd thing is that u cannot leave a fraction in the answer. if it is [1/3,0,1]. make it this way. [103] u have multiplied everything by 3. the plane's brackets they have given is just to confuse you. Hope this helps.

don think of the starting point of the vector. find coordinates of the vector where it ends. Shift origin u have problems with some. Then u can easily find out.

this particularly helps marcia and bonjo

not getting it.

plz sum body post the answer

thanks picha lite...the BRACKETS are what that have puzzled me all these hours..@ Anonyms, the question asks for the direction of the vectors in the x,y and z directions i.e. [xyz] not (xyz). So the first vector is pointing downward 1 unit along the vertical direction i.e. z=-1. Then it goes 1/3 along the x i.e. x=1/3. Finally, the y direction is not taken i.e. y=0. Then applying the previous posts esp by picha will help you with the rest of the other vectors...

plz bonjo