Maybe a problem keeping it in a pressure vessel, but it might be possible to produce such high pressures at very small scales in solid state devices without use

Maybe a problem keeping it in a pressure vessel, but it might be possible to produce such high pressures at very small scales in solid state devices without use of a pressure vessel. In that case it would be more about changing the shape or bond angle of some nearby material to distort the electric field and induce the desired pressure.