An Assessment of Alternative Low Level Calculation Methods for the Initial Selection of Conformers of Diastereomeric Esters
Table 3
The number of conformers found by optimization with LLMs and HF/STO-3G (Steps 1 and 2, Step 4 (the first level), resp., Figure 2) as well as with the RefM2 (entire Step 4, Figure 2) within certain energy ranges.
Energy range from 0.00 to āākcal/mol
RefM2
HF
UFF
Dreiding
AM1
PM3
PM6
MM3
MM+
COFC energya
11
11
35
97
87
94
76
55
37
2,50
46
54
35
111
109
159
28
39
71
2,00
43
42
23
81
78
132
27
29
64
1,50
33
42
10
49
60
89
14
26
51
1,00
11
11
6
17
32
41
10
11
26
0,75
9
4
4
13
18
26
10
4
16
The COFC energy values for LLMs are given in Table 2.