Figure 4.

Reorientation of equivalent atoms (above) and determining the new position of the transferred H (below). (a) Exchanging the positions of the equivalent Os of OAc^–. Dummy Hs are marked with a green circle. As the O without the dummy H(O1) is closer to the donated proton than O2, their positions are swapped. After the transfer, the position of the H of HOAc is also updated. The unnaturally long O–H bond in the middle step does not lead to problems, as there are no simulation steps during the reorientation. (b) The exact mechanism of setting the new position of the transferred H. The molecules before the transfer are shown on the left. The new position (marked with an x) is calculated to lie on the acceptor atom—donated H line, 1 Å from the acceptor. The right side shows the molecules after the transfer, with the H at its new position. Dummy atoms are shown in green.