Molecules change the shape in energy-minimization step

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1

GROMACS version:4.5.5
GROMACS modification: No

Hi Gromacs users,

I want to keep the water shape in the energy-minimization step.
The HO bond length of Tip4p_ice water is 0.9572 A
but after the minimization, the bond length usually becomes ~0.97 A

I tried the Shake constraint in the energy-minimization step, but it shows that there are some errors, it can not work in the energy-minimization step.

I am not sure where the problem is. Does anyone have any suggestions?

2

Use SETTLE to constrain the water geometry. See any of the standard water topologies in GROMACS to make sure your topology has the right [settles] settings.

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