Hi friends,

I want to do MD simulation, but after I have put my ligand-receptor complex into an orthorhombic box and solvated with explicit periodic boundary solvation water model, and then subject to CHARMm forcefield and minimization (500 steps of steepest descent and 500 steps of conjugated gradients), I get errors for dynamics (heating or cooling) with system saying CHARMm has terminated check CHARMm Log File, with error information (CHARMm dynamics simulation has failed because energy change tolerance exceeded). I am new to it and don't know why. Can anyone assist me on this.