We chose Gaussian envelopes of the pump and probe pulses, E a (t) = exp{-(t/τ a ) 2 } and E a (ω) = exp{-(ωτ a ) 2 /4} (a = pu, pr), in which the pulse duration τ a is set to 5 fs. This yields the pulse bandwidth 0.44 eV (full width at half maximum). In our simulations, polarization-sensitive effects and orientational averaging are not explicitly considered, which is equivalent to replacing the scalar products of the kind |ε ε ε pu µ µ µ ge (R g )| 2 by scalar coefficients |µ µ µ ge (R g )| 2 in the DW functions. Within the DW formalism, the aforementioned effects can be taken care of as demonstrated in Ref. .