  We show using density functional calculations that quasi-one-dimensional
K2Mo3As3, which is closely related to the K2Cr3As3 and has very similar
superconducting properties, is not close to magnetism and has conventional
s-wave electron-phonon superconductivity. This superconductivity is of
multi-gap character due to different coupling on different Fermi surface
sheets. This is discussed in relation to the properties of this family of
quasi-one-dimensional pnictide superconductors. The results show that this
family of superconductors provides a unique opportunity for studying the
interplay of spin-fluctuations and electron-phonon superconductivity in
transition metal pnictides and offer a path for sorting out the different
proposed superconducting scenarios in this fascinating family of pnictide
superconductors.
