  We propose that the quasi-one-dimensional molybdenum selenide compound
Tl2-xMo6Se6 is a time-reversal-invariant topological superconductor induced by
inter-sublattice pairing, even in the absence of spin-orbit coupling (SOC). No
noticeable change in superconductivity is observed in Tl-deficient (0<=x<=0.1)
compounds. At weak SOC, the superconductor prefers the triplet d vector lying
perpendicular to the chain direction and two-dimensional E2u symmetry, which is
driven to a nematic order by spontaneous rotation symmetry breaking. The
locking energy of the d vector is estimated to be weak and hence the proof of
its direction would rely on tunnelling or phase-sensitive measurements.
