Algorithm A1.

Iterative fitting of the chain length mismatch correction to a linear function Parameters behind; in function definitions designate fixed inputs in the optimizations Data inputs are Δl_C, σ_CH3

$$\begin{array}{cc}\hfill & \mathbf{function}Flin(k,{\sigma }_{CH3}^{sym};\mid \Delta l_{C,corr}\mid )\hfill \\ \hfill & \hfill \\ \hfill & \mathbf{return}k\mid \Delta l_{C,corr}\mid +{\sigma }_{CH3}^{sym}\hfill \\ \hfill & \hfill \\ \hfill & \mathbf{function}Fcorr(d_{tilt};\Delta l_C,k,{\sigma }_{CH3}^{sym})\hfill \\ \hfill & \hfill \\ \hfill & \mid \Delta l_{C,corr}\mid \leftarrow \mid \Delta l_C+d_{tilt}\mid \hfill \\ \hfill & \hfill \\ \hfill & \mathbf{retun}k\mid \Delta l_{C,corr}\mid +{\sigma }_{CH3}^{sym}\hfill \\ \hfill & \hfill \\ \hfill & \mathrm{initialize}:k,{\sigma }_{CH3}^{sym},d_{tilt},\mid \Delta l_{C,corr}\mid \hfill \\ \hfill & \hfill \\ \hfill & \mathbf{while}\mid Flin-Fcorr\mid >\epsilon \mathbf{do}\hfill \\ \hfill & \hfill \\ \hfill & k,{\sigma }_{CH3}^{sym}\leftarrow \text{optimize}Flin-{\sigma }_{CH3}=0\hfill \\ \hfill & \hfill \\ \hfill & d_{tilt}\leftarrow \text{optimize}Fcorr-{\sigma }_{CH3}=0\hfill \\ \hfill & \hfill \\ \hfill & \mathbf{end}\mathbf{while}\hfill \end{array}$$