You had the right idea. Angstroms are not an SI unit. The SI units jump by three orders of magnitude at this scale: picometer, nanometer, micrometer, millimeter.

(In the same way that meter jumps three orders of magnitude to kilometer[1], or millions to billions to trillions, etc.)

[1] Technically there are intermediate SI units between meter and km but nobody uses them. There are not intermediate SI units between the tiny ones.