The electronic, optical, and thermodynamical properties of tetragonal, monoclinic, and orthorhombic
M
3
N
4
(
M
= Si, Ge, Sn): A first-principles study
Chen Dong
1, †
, Cheng Ke
2
, Qi Bei-Ying
1
(color online) The same as Fig.
1
, but for o-
M
3
N
4
(
M
=Si, Ge, Sn).