Dear Amber Users,
due to the larger flexibility of the gaussian input format, I would like
to substitute the divcon program by g03 for the calculation of AM1-BCC
charges used as GAFF parameters of small molecules. In prinziple, this
works pretty well after some modifications of the antechamber program.
But the AM1-BCC charges are much different to the original results using
divcon. Here are the results for ethanol as an example:
antechamber/divcon
.<TRIPOS>MOLECULE
C2H5OH.log
9 8 1 0 0
SMALL
bcc
.<TRIPOS>ATOM
1 C -2.0090 1.0490 0.3220 c3 1 UNK 0.1311
2 H -1.6570 0.0250 0.3970 h1 1 UNK 0.0183
3 H1 -3.0920 1.0400 0.3970 h1 1 UNK 0.0182
4 O -1.4240 1.8760 1.3520 oh 1 UNK -0.6024
5 H2 -1.6570 1.5470 2.2310 ho 1 UNK 0.3976
6 C1 -1.5780 1.6590 -1.0070 c3 1 UNK -0.0970
7 H3 -1.9780 1.0930 -1.8390 hc 1 UNK 0.0380
8 H4 -1.9310 2.6800 -1.0670 hc 1 UNK 0.0480
9 H5 -0.4970 1.6670 -1.0670 hc 1 UNK 0.0482
.<TRIPOS>BOND
1 1 2 1
2 1 3 1
3 1 4 1
4 1 6 1
5 4 5 1
6 6 7 1
7 6 8 1
8 6 9 1
.<TRIPOS>SUBSTRUCTURE
1 UNK 1 TEMP 0 **** **** 0 ROOT
antechamber/g03
.<TRIPOS>MOLECULE
C2H5OH.log
9 8 1 0 0
SMALL
bcc
.<TRIPOS>ATOM
1 C -2.0090 1.0490 0.3220 c3 1 UNK 0.1393
2 H -1.6570 0.0250 0.3970 h1 1 UNK 0.0203
3 H1 -3.0920 1.0400 0.3970 h1 1 UNK 0.0202
4 O -1.4240 1.8760 1.3520 oh 1 UNK -0.6169
5 H2 -1.6570 1.5470 2.2310 ho 1 UNK 0.4005
6 C1 -1.5780 1.6590 -1.0070 c3 1 UNK -0.0929
7 H3 -1.9780 1.0930 -1.8390 hc 1 UNK 0.0382
8 H4 -1.9310 2.6800 -1.0670 hc 1 UNK 0.0457
9 H5 -0.4970 1.6670 -1.0670 hc 1 UNK 0.0457
.<TRIPOS>BOND
1 1 2 1
2 1 3 1
3 1 4 1
4 1 6 1
5 4 5 1
6 6 7 1
7 6 8 1
8 6 9 1
.<TRIPOS>SUBSTRUCTURE
1 UNK 1 TEMP 0 **** **** 0 ROOT
Differences of other atom types like sulfur are even more severe and can
be seen already in the AM1 charges before the bond corrections are
applied. To my understanding, Mulliken population analysis based on AM1
should give exactly the same results independent of the program used.
Can anybody explain these deviations and perhaps help me in creating a
gaussian input file reproducing the divcon results?
Thank you very much for your help.
Thomas
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Received on Wed Jan 23 2008 - 06:07:27 PST
