  The motional electric field experienced by an H2+ ion moving in a magnetic
field induces an electric dipole, so that one-photon dipole transitions between
rovibrational states become allowed. Field induced spontaneous decay rates are
calculated for a wide range of states. For an ion stored in a high-field (B ~
10 T) Penning trap, it is shown that the lifetimes of excited rovibrational
states can be shortened by typically 1-3 orders of magnitude by placing the ion
in a large cyclotron orbit. This can greatly facilitate recently proposed [E.
G. Myers, Phys. Rev. A 98, 010101 (2018)] high-precision spectroscopic
measurements on H2+ and its antimatter counterpart for tests of CPT symmetry.
