Based on the theory of surface lattice dynamics, the surface phonon spectrums along three symmetrical directions of
$\bar \varGamma \bar L$
,
$\bar L\bar M$
and
$\bar \varGamma \bar M$
are simulated for the W(100) surface by using the modified analytic embedded atom method. The polarization vectors at different symmetrical points are also calculated. According to the criterion and marking method of surface mode, the surface modes along different symmetrical directions are drawn, the distribution range and mode coupling of surface modes are discussed as well. The vibration frequencies of surface modes calculated by us have been compared to available experimental datum and some theoretical values correspondingly. The results display that the present results are general agreement with the referenced experimental or theoretical results. Based on the calculated polarization vector, the surface vibration states are constructed for the atomic layers in the neighboring surface. And the polarization and local features of the surface modes along different symmetrical directions are analyzed. The results show that there are some coupling phenomena between surface mode dispersion, such as avoid crossing and independence crossing. The avoid crossing is found between the surface-mode branch S
1and the surface-mode branch S
2near
${\bar \zeta _y} = 0.32$
along
$\bar L\bar M$
direction. In the region, going from
$\bar L$
to
$\bar M$
, S
1changes from
ypolarization to
zpolarization, and S
2changes from
zpolarization to
ypolarization. The independence crossings exist between surface-mode branch S
1and surface-mode branch S
2at
${\bar \zeta _x} = 0.5$
along
$\bar \varGamma \bar L$
direction, and surface-mode branch S
2and surface-mode branch S
3at
${\bar \zeta _x} = 0.5$
along
$\bar L\bar M$
direction, respectively. Before and after the crossings, the polarization and local features of the surface modes have not changed. Inspection of the polarization vectors, the coupling phenomena are iconically demonstrated.
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