A method and control sequence determination facility for determining a magnetic resonance system activation sequence that includes a multichannel pulse train with a plurality of individual HF-pulse trains to be emitted by the magnetic resonance system via different independent high-frequency transmit channels of a transmit facility in a parallel manner are described. The multichannel pulse train is calculated based on a k-space gradient trajectory and a predetermined target magnetization using an HF pulse optimization method. In the HF pulse optimization method, optimization of the multichannel pulse train and/or the k-space gradient trajectory takes account of at least one hardware operating parameter of the transmit facility.