  The relativistic configuration interaction valence bond method has been used
to calculate permanent and transition electric dipole moments of the KRb
heteronuclear molecule as a function of internuclear separation. The permanent
dipole moment of the ground state $X^1\Sigma^+$ potential is found to be
0.30(2) $ea_0$ at the equilibrium internuclear separation with excess negative
charge on the potassium atom. For the $a^3\Sigma^+$ potential the dipole moment
is an order of magnitude smaller (1 $ea_0=8.47835 10^{-30}$ Cm) In addition, we
calculate transition dipole moments between the two ground-state and
excited-state potentials that dissociate to the K(4s)+Rb(5p) limits. Using this
data we propose a way to produce singlet $X^1\Sigma^+$ KRb molecules by a
two-photon Raman process starting from an ultracold mixture of doubly
spin-polarized ground state K and Rb atoms. This Raman process is only allowed
due to relativistic spin-orbit couplings and the absence of gerade/ungerade
selection rules in heteronuclear dimers.
