Atomic and Molecular Physics Question on Atoms

Question

Apart from the acoustic modes, 9 optical modes are identified from the measurements of phonon dispersions of a solid with the chemical formula $A_nB_m$ , where $A$ and $B$ denote the atomic species, and $n$ and $m$ are integers. Which of the following combinations of $n$ and $m$ is/are possible?

Accepted Answer

$n = 2, m = 2$

Atomic and Molecular Physics Question on Atoms

Solution