Hello Amber Community
I have optimized ethanol molecule at HF/6-31g(d) level and calculated the esp charges at the same level with following guassian keywords Scf=tight pop=mk Iop(6/32=2, 6/41=10,6/42=17). Antechamber gives a resp charges below as shown below
.<TRIPOS>MOLECULE
ETH
9 8 1 0 0
SMALL
resp
.<TRIPOS>ATOM
1 C1 -0.0290 0.5450 0.0000 c3 1 ETH 0.566448
2 C2 1.1650 -0.3870 0.0000 c3 1 ETH -0.216837
3 O1 -1.1940 -0.2390 0.0000 oh 1 ETH -0.723897
4 H1 0.0010 1.1890 0.8780 h1 1 ETH -0.099119
5 H2 0.0010 1.1890 -0.8780 h1 1 ETH -0.099119
6 H3 1.1470 -1.0220 0.8790 hc 1 ETH 0.052386
7 H4 1.1470 -1.0220 -0.8790 hc 1 ETH 0.052386
8 H5 2.0920 0.1780 0.0000 hc 1 ETH 0.052386
9 H6 -1.9570 0.3220 0.0000 ho 1 ETH 0.415368
.<TRIPOS>BOND
1 1 2 1
2 1 3 1
3 1 4 1
4 1 5 1
5 2 6 1
6 2 7 1
7 2 8 1
8 3 9 1
.<TRIPOS>SUBSTRUCTURE
1 ETH 1 TEMP 0 **** **** 0 ROOT
My concern is the negative charges on the hydrogen attached to the C1 makes the results appear quite unreasonable to me. Again, when i use the same method for 1-butyl-3-methyl-3-imidazolium chloride ionic liquid according united atom method employed by Liu et.al J.Phys.Chem.B.2010,114,4572,4572-4582, it produces similar negative charges on the hydrogen atom attached to the C2 carbon on the alkyl chain. I must add that no published paper have reported such negative charges in 1-butyl-3-methyl-3-imidazolium chloride ionic liquid. Could somebody help me understand why am getting these charges. Thanks in advance.
Alex
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Received on Thu Sep 02 2021 - 08:30:02 PDT
