[gmx-users] oscillational period problem in Martini force field

[Du Jiangfeng (BIOCH)]

Dear Friends,

I am doing MD simulation to a coarse grained system by using martini force field. According to Martini recommendation, the MD time step should be in 20-40 fs. 
Since I selected 20 fs, the warning comes: "estimated oscillational period is less than 5 times of the time step".
I could erase the warning by decreasing the time step to 8 fs, which is not recommended by Martini force field. 

Here is my question: Should I ignore this warning or decrease time step or struggle with the protein system (the system seems not to be improved any more) ?

Any reply would be appreciated,

Thank you    

    Jiangfeng Du, PhD Student
    Cardiovascular Research Institute Maastricht
    Department of Biochemistry
    P.O. Box 616
    Mobile: +31-681741859
    FAX: +31-43-3884159
    6200 MD Maastricht
    The Netherlands