source leaprc.gaff2
source leaprc.water.tip3p
loadamberparams frcmod.ionsjc_tip3p
loadamberparams frcmod.graphene
loadoff graphen.off
GRAPHEN = loadpdb graphen_wat1.pdb
check 
savepdb GRAPHEN graphen2.pdb
saveamberparm GRAPHEN graphen.prmtop graphen.rst7
