I want to create an image that looks like this:
How can I recreate this effects, or what terms should I use for finding better results?
I don't believe this can be made exclusively with Gimp.
I can't be 100% sure what program produced that rendering, but if I had to guess I would think it was the free program, Chaoscope. It is a Windows or Linux program that allows you to render 3d abstractions and fractacls it generates with various algorithms.
I briefly tried to replicate the image above using a random generator of a polynomial function. I rendered it and it came out like this:
I then applied a colorful gradient and cropped it so it was similar to your output
To produce better results you would want to play with the function options that create these abstract renderings. You would also consider rendering the finished product for longer to remove the graininess. I generally haven't seen people using this technique as the main pillar for their design, but it is often used for secondary detail.
A thought experiment: requires software that supports gradients, layers, transparency and layer blending modes.
Place a b&w (greyscale) photo of drapery with the ripples of drapery running horizontally on a layer in and RGB document.
Place purple-red-yellow gradient on a 2nd layer (on top) and set the layer mode to "overlay".
Place a b&w photo of high-magnification crystal lattice structure on a top layer set the layer mode to "lighten" or "screen".
Obviously, rather than using a B&W photo, you could use a white brush with "size and rotation dynamics" or any other source of marks. The key is to work in B&W "masks" or to work white to transparent etc.
A quick google image search for "gimp tutorial abstract" gave several possibilities, such as this which is certainly a good place to start.