[gmx-users] new residue went into crash during energy minimization

[Wang Tao]

Hello,everyone!

I am using charmm27 in gromacs for simulation of a double strand DNA , of which a residue is modified by a group.The forcefield parameters for the new residue is generated with swissparam.
After conducting energy minimization , i checked the DNA's structure with pymol . Obviously , some thing is wrong .   Except for the atoms in the back bone , all the atoms in the modified residue are seperated from each other .
What can i do to make it though the energy minimization?

Thank you!
 Tao Wang