Hi all,
I've noticed that the total charge of a DMPC lipid (as computed by tleap) is not 0. I've created a pdb file with one DMPC lipid (see github gist link below), which I run through tleap as follows:
source leaprc.lipid14
source leaprc.ff14SB
loadamberparams frcmod.ionsjc_tip3p
mol = loadpdb dmpc.pdb
charge mol
>>> Total unperturbed charge: -0.000006
>>> Total perturbed charge: -0.000006
pdb file here:
https://gist.github.com/mpharrigan/2b43a3bb5dcdb9bd2c94
This may look like a rounding error, but it scales linearly in number of lipids. For a full size membrane system, it results in a noticeable charge; order 0.02e. Should I be worried about this? Why do these lipids appear to be charged?
Thanks,
Matt
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Received on Tue Dec 02 2014 - 22:30:02 PST
