Dear GMXers,<br><br>I'm trying to implementing a flexible water model in "Gordillo, M.C.; Marti, J. <i>J. Phys.: Condens. Matter</i> <b>2010</b>, <i>22</i>, 284111" using GROMACS.<br><br>The intra-molecular water potential has the following form:<br>
V=D{[1-exp(-alpha*r1)]^2 + [1-exp(-alpha*r1)]^2} + k_a /2 *r3^2 + k_a*r3*(r1+r2) + k_rr *r1*r2<br>where r1, r2 is the O-H bond distance and r3 is the H-H distance.<br><br>The first term can be modeled using Morse potential.<br>
The second term can be model by harmonic potential.<br><br>Could anyone give some suggestions about how to implement the remaining two coupling terms in GROMACS? Or can anyone recommend other packages that support these function forms?<br>
<br>Thank you.<br><br>Best,<br>Yanbin<br>