AMBER Archive (2004)

Subject: AMBER: Atom type

From: L Jin (
Date: Wed Jan 07 2004 - 05:26:25 CST


Does anybody have the experience to introduce a new atom type into the current
AMBER7 forcefield? I tried to add in one atom type SO for Sulfure. I write an
frcmod file including 'Mass, bond, angle, dihedroangle' and load it together
with parm99 to leap. After I modified my molecule structure, I used 'check' and
leap did not complain anything except a warning about the net charge -1.997,
which is not important. But I simply cannot save top & crd files with the
message that 'cannot find the SO type'. I have load it and no complain when
checking the molecule. Any comments or suggestions about this? Thanks in advance.


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