Minecraft – Particle Help On Commands

XD, YD, and ZD usually mean the difference in X, Y, and Z that the particles can appear in from the coordinates that you gave. This means that rather than all being summoned at an exact point, the particles can cover an area.

For example, /particle smoke ~ ~ ~ 10 0 0 0 100 will create a long line of particles along the X axis. /particle smoke ~ ~ ~ 1 1 1 0 100 will create a small box.

This does not affect the movement of individual particles though, you most likely want the <speed> argument. If you make this 0, the particles should not move as much. Keep in mind though that many particles inherently have some small movement that is unavoidable.

Data tags have the form name : value. The name/value separator is :. You need to put : between the name (ench) and the value ([{id:49,lvl:100,{id:51,lvl:1}}]) of the tag.

There is also a typo in the value itself. Each enchantment has to be given as a compound tag, enclosed in curly brackets. You need to close the first enchantment by putting } after lvl:100, then remove the duplicate one at the end:

ench:[{id:49,lvl:100},{id:51,lvl:1}]