  The operator for interaction between monochromatic electromagnetic field
(light) and molecules is usually presented as a two multipolar series %
truncated expansions $V^{E1}+V^{E2}+...$ (electro-dipole,
electro-quadrupole,...) and $V^{M1}+V^{M2}+...$ (magneto-dipole,
magneto-quadrupole, ...). The optical transition probability is proportional to
the complex square of the sum of these series, which contains interference
terms like $V^{En}V^{En'}$, $V^{Mn}V^{Mn'}$, and $V^{Ep}V^{Mk}$ ($n\ne n'$). In
the present study it is shown that all of terms $V^{Ep}V^{Mk}$ may be observed
experimentally, if the the molecules are oriented, electrically and
magnetically, and the light with appropriate phase shift between electric and
magnetic fields. Also, a simple operator for the light-molecule interactions is
proposed, as an alternative to Taylor series mentioned above.
