While keeping these limitations in mind, let us point out a suggestive structural feature seen in both force fields (Fig. , see also Fig. ): There appears to be an odd/even variation such that at any even DMPC tail carbon segment (such as 6/6') the interchain S CH difference is smaller than at the neigboring odd segments (5/5' and 7/7'). This feature can not be confirmed with our experimental resolution, but it may be related to a previously reported odd/even effect on C-C bond order parameters S CC . Let us then turn to the dehydration responses.