An open-framework hybrid solid with two different types of manganese phosphate chains has been synthesized under solvent-free conditions. A type I chain consists of isolated Mn2O(10) dimers, while a type II chain contains an infinite Mn-O-Mn chain constructed from corner-sharing Mn2O10 dimers. The compound shows ferrimagnetic behavior, which is different from the antiferromagnetic behavior for its structural analogue that only contains type I manganese phosphate chains.