Manually Positioning Particles doesn't work

I already looked at this previous question:Setting particle position does not appear work - Questions & Answers - Unity Discussions
However even if I set particleEmitter.particles[0].position.x = 5; directly it still does not work. Very puzzled by this. Currently I have attached to a blank gameobject:

a very tiny ellipsoi particle emitter which emits one particle with no velocity, 0 for the minenergy and maxenergy so it never disappears, and oneshot on

a particle renderer with nothing changed

this script:

function FixedUpdate(){

`a = particleEmitter.particles[0].position.x = 5;`

`Debug.Log(a);`

`Debug.Log(particleEmitter.particles[0].position.x);`

}

The particle does not move, ‘a’ returns 5, and the second Debug returns the position of the emitter as if the particle had not moved which it hasn’t.
Can anyone explain? Or provide an example which works?

As with all cases like this, you have to get a copy, change the copy, then assign it back. (See the docs.)