Euler buckling with ansys

 1) anaylitical model:

Vertical Cylindrical beam under axial compression load

Height: 26.5mm, Radius: 1.25mm, E: 200000, Load factor k: 2,
Pcritical: 1,347N, Displacement: 0.0364mm 

 2) Beam188 model worked fine with results similar to
analytical one. (txt file attached)

3) Solid186 mold under predicts by a factor of 4 (txt file
attached)

why does the solid 186 element give different results?

Thanks

H Jishi