Hello,
I am trying to optimize (5,0) single walled carbon nano-tubes using Gaussian 09. I am having trouble the geometry distorting after running in the HF STO basis set and higher. The process of me making the nanotube comes from using TubeGen Online in which I constructed the atom to have hydrogens on the end. I have attached images of the structure that looks like it optimized well and the next basis set up I ran it on and distortion that happened
Here is an example of my geometry optimization input files in which I am running the geometry optimizations on
%chk=C:\Users\goytia54\Desktop\CNT_HFSTO.chk
# opt rhf/sto-3g geom=connectivity
Title Card Required
0 1
C 1.41648700 -0.17875800 -2.01412400
C 2.85923300 -0.17799900 -2.01226800
C -0.71814900 -1.33148100 -1.52908600
C 0.71669100 -1.33405700 -1.53245500
C 1.41648200 -1.96996400 -0.45481100
C 2.85905600 -1.96877900 -0.45317500
C -0.71791500 -1.86640500 0.79602200
C 0.71703300 -1.86846900 0.79296700
C 1.41923900 -1.03913500 1.72837500
C 2.86255600 -1.03823200 1.72987400
C -0.71712600 0.17981200 2.02353200
C 0.71776800 0.17747400 2.02012500
C 1.42114700 1.32216600 1.51845700
C 2.86491000 1.32357200 1.52057200
C -0.71678000 1.97940700 0.45656000
C 0.71804400 1.97669200 0.45339600
C 1.41940800 1.85577100 -0.79161100
C 2.86240100 1.85643800 -0.79013500
C -0.71765700 1.04502600 -1.73873200
C 0.71733900 1.04281600 -1.74212100
C -1.41780300 1.85968200 -0.78884200
C -1.42079900 -0.17603700 -2.00699400
C -1.42080000 -1.96392100 -0.45034600
C -1.41799000 -1.03730200 1.73347900
C -1.41611100 1.32845200 1.52574400
C 3.53443900 -1.87650600 0.79621700
C 3.53348100 -1.33736900 -1.53627200
C 3.53445700 1.04709900 -1.74833600
C 3.53624200 0.17791600 2.03360100
C 3.53627200 1.98830600 0.45685500
H 4.60792000 0.19726000 2.26122800
H 4.60745300 -2.08384400 0.88406900
H 4.60727000 1.16347300 -1.94292700
H 4.60692300 -1.48545700 -1.70605100
H 4.60738600 2.21404700 0.50821600
C -2.86061600 -1.03838200 1.73165900
C -3.53516400 -1.87628200 0.79984500
C -2.86392500 -1.96550000 -0.45197300
C -3.53388000 0.18038200 2.02845100
C -2.85824600 1.32711800 1.52354300
C -2.86409500 -0.17706400 -2.00854700
C -3.53651600 -1.34046400 -1.53928900
C -2.86022500 1.85851600 -0.79000900
C -3.53340700 1.98611000 0.45760800
C -3.53543700 1.05036800 -1.74789700
H -4.60828200 2.19833500 0.50659000
H -4.60659200 0.20081400 2.25574000
H -4.60755200 1.16855000 -1.94328200
H -4.60776900 -1.49181000 -1.71303600
H -4.60700400 -2.08747000 0.89031300
1 2 1.5 4 1.5 20 1.5
2 27 1.5 28 1.5
3 4 1.5 22 1.5 23 1.5
4 5 1.5
5 6 1.5 8 1.5
6 26 1.5 27 1.5
7 8 1.5 23 1.5 24 1.5
8 9 1.5
9 10 1.5 12 1.5
10 26 1.5 29 1.5
11 12 1.5 24 1.5 25 1.5
12 13 1.5
13 14 1.5 16 1.5
14 29 1.5 30 1.5
15 16 1.5 21 1.5 25 1.5
16 17 1.5
17 18 1.5 20 1.5
18 28 1.5 30 1.5
19 20 1.5 21 1.5 22 1.5
20
21 43 1.5
22 41 1.5
23 38 1.5
24 36 1.5
25 40 1.5
26 32 1.0
27 34 1.0
28 33 1.0
29 31 1.0
30 35 1.0
31
32
33
34
35
36 37 1.5 39 1.5
37 38 1.5 50 1.0
38 42 1.5
39 40 1.5 47 1.0
40 44 1.5
41 42 1.5 45 1.5
42 49 1.0
43 44 1.5 45 1.5
44 46 1.0
45 48 1.0
46
47
48
49
50