Paper: CSIR-NET December 2019 · Subject: Physical Chemistry · Chapter: Group Theory · Topic: Symmetry Elements Point Groups · Marks: 2 · Difficulty: Medium
For every atom that is NOT shifted under $\mathrm{C}_{4}$ and $\sigma$ symmetry operations, the characters are respectively.
(a)$-1,-1$
(b)0,0
(c)1,1
(d)$-1,1$
Answer
Answer: C ✓ checked by 4AB · confidence high
Explanation
An unshifted atom contributes χ(C₄) = 1 + 2cos90° = 1 and χ(σ) = 1 (c).