Using the pruned-enriched Rosenbluth Monte Carlo algorithm, the scattering functions of semiflexible macromolecules in dilute solution under good solvent conditions are estimated both in d 2 and d 3 dimensions, considering also the effect of stretching forces. Using self-avoiding walks of up to N 25 600 steps on the square and simple cubic lattices, variable chain stiffness is modeled by introducing an energy penalty ε _b for chain bending; varying q _b exp (-ε _bk _BT) from q _b 1 (completely flexible chains) to q _b 0.005, the persistence length can be varied over two orders of magnitude. For unstretched semiflexible chains, we test the applicability of the Kratky-Porod worm-like chain model to describe the scattering function and discuss methods for extracting persistence length estimates from scattering. While in d 2 the direct crossover from rod-like chains to self-avoiding walks invalidates the Kratky-Porod description, it holds in d 3 for stiff chains if the number of Kuhn segments n _K does not exceed a limiting value n _K ~* (which depends on the persistence length). For stretched chains, the Pincus blob size enters as a further characteristic length scale. The anisotropy of the scattering is well described by the modified Debye function, if the actual observed chain extension X (end-to-end distance in the direction of the force) as well as the corresponding longitudinal and transverse linear dimensions X ~2 - X ~2, R _(g,τ) ~2 are used.
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