Footnote: Looked in my German science dictionary, and the verb küren*. is defined as to choose, elect.

Words in science or technical fields may depart from meanings or frequency of use in German speech, e. g.,
kören is neither obsolete nor rare in technical German writing; in the broad sense it means to assay, or to inspect but in certain senses, to select.

auserkoren*, as chosen, selected, also is common in German scientific writing (as well as common speech, if I am reading you correctly, Wolfgang?).

erkiesen, according to my dictionaries, as Wolfgang says, is found in poetic use, along with erkoren, but not in ordinary speech (old German songs, as Wolfgang says).

I had to read a lot of technical German but I have lost a lot since I retired. Unfortunately I never learned to speak German. Technical German is quite different from spoken German.