I have tried to use the "compute_dos" command to calculate the PDOS of a single
layer graphene with opt-Tersoff potential and EMD method. The output is very
similiar with that in ex2 of gpumd.
According to references of Balandin, there should be two peaks around 1350 cm-1
(or 40.5 THz) and 1585 cm-1 (or 47.55 THz) for the in-plane phonons,
corresponding to TO mode around BZ edge and LO/TO mode around BZ origin,
respectively. However, the 1350 cm-1 peak is missing in both my calculations
and ex2. Thus, could you help me explain that why the peak in 1350 cm-1 is
missing? Is it possible to get the peat around 1350 cm-1 by just optimizing
parameters in ex2? Thank you very much!