Text this: The crystal structure of poly(triaqua-(m 2-2,2′-bipyridine-4,4′-dicarboxylato-K 2 O:O′)-bis(m 2-2-2′-bipyridine-4,4′-dicarboxylato-K 4 O,O′:O″:O‴)dierbium(III)) hydrate, C36H26Er2N6O16