Chain length alternation, hydrogen bonds

The fact that doping does indeed largely perturb the geometry of ID chains has been confirmed by several computer experiments on isolated chains of equidistant hydrogen atoms [49] and on a more realistic model of polyacetylene [50]. In both cases, the doping is shown to have the same effect, i.e. the amount of bond alternation is calculated to be drastically reduced bond lengths of 1.41 and 1.43 A versus 1.33 and 1.48 A for the double and single bonds, respectively (already in minimal basis sets calculations). 

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