About wrong answers given in assignments solution

[Madhuri Bhattacharya]

Respected sir,

This is Madhuri Bhattacharya, a research scholar from the chemistry department of IIT Madras. I have taken this crystallography nptel online course. I have found out some contradictions and error in the solutions given in assignment no 5 and 1.

In assignment no 5, question no 6 has first and last options same. I had chosen the first option but it is showing wrong although in solution the same answer is given. So I think it is taking only the last option as correct. As both the first and last option are same here, so please give marks for selecting any of them.

Again in assignment no 5, in question no 15, I think wrong answer is given. It's statement was 'Reciprocal lattice volume for orthorhombic space group is abc'. I had marked false as it should be 1/abc, but the solution is given as true statement. So please rectify the solution.

Also in assignment no 1, in question no 12, I think wrong answer is given. Its statement was 'There are 7 crystal systems which constitute 14 Bravais lattices, which when combined with 32 point groups, give rise to 230 space groups'. I had marked false as we have to consider screw axis and glide planes along with these to get 230 space groups. The solution is given as true statement. So please rectify the solution.

Here I have attached the screenshots of these questions and the screenshots of supporting pages from the pdf version of this course for the reference.

Hope you will do the needful.

Best regards,

Madhuri Bhattacharya.