In summary, we performed force-field based classical molecular dynamics simulations for nine different imidazoliumbridged dinucleotide intermediates bound to a templating strand with complementary WC base pairing partners, downstream of the 3 ′ -end of the copied strand (primer). These simulations allow us to shed more light on experimentally observed rate and fidelity of nonenzymatic RNA template copying reactions and explain the differences between different systems containing biological and alternative ribonucleotides.