Re: [AMBER] help with RESP tutorial using antechamber and gaussian

From: FyD <>
Date: Mon, 23 Sep 2013 08:29:30 +0200

Dear Fengxue Li,

> I used antechamber implemented in AMBER11package to derive Resp
> charge for a organic molecule:diethylamine. Its consists of 17
> atoms, and a net charge of +1.

The total charge of diethylamine equals zero & not +1.

> I followed the following procedure to derive resp charge:
> [1] Optmized at HF/6-31g* and did single point energy
> calculation#HF/6-31G* SCF=tight Test Pop=MK iop(6/33=2) iop(6/41=10)
> iop(6/42=8)
> will creat "name.log", and sum of Mulliken charges with hydrogens
> summed into heavy atoms = 1.00000

the total charge of an alkyl amine equals 0
the total charge of an ammonium equals +1

> [2] Then i used antechamber the following command to derive resp charge
> antechamber -i name.log -fi gout -o name.prepi -fo prepi -c resp -s 2
> This will creat the required resp input files for our molecule,the
> resp charges will end up in the "name.prepi" file,but the charge of
> all atoms is 0.000002 in the 'name.prepi' file.

this is correct (with a rounding off error, which equals +2.10-6).

> Can anyone help me to derive resp charge for this system..

May be better define the total charge of your molecular system, and
then run the code. You could also use the R.E.D. tools or R.E.D.
Server at to derive RESP charges and generate
force field libraries.

regards, Francois

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Received on Sun Sep 22 2013 - 23:30:02 PDT
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