EFFECTS OF THE CUTOFF CENTER ON THE MEAN POTENTIAL AND PAIR DISTRIBUTION-FUNCTIONS IN LIQUID WATER

Molecular dynamics simulations of extended simple point charge (SPC/E) water have been performed to study the effects of the truncation of l ong-range interactions on some calculated bulk properties of the Liqui d. The mean potential calculated in liquid water is sensitive to the c hoice of the cutoff center in the water molecule. The pair distributio n function is also dependent on this choice, although not as strongly as the mean potential. An analysis is carried out to understand the or igin of these effects. A common cutoff center is at the oxygen atom in the water molecule, but our study shows that this choice does not yie ld a mean potential value consistent with a more accurate estimate whe n no cutoff is applied. (C) 1995 by John Wiley & Sons, Inc.