Hello,
I ran the following optimisation of triazine:
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User input:
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$molecule
0 1
N1
C1 N1 cn
N2 C1 cn N1 ncn
C2 N2 cn C1 cnc N1 dih1
N3 C2 cn N2 ncn C1 dih1
C3 N3 cn C2 cnc N2 dih1
H1 C1 hc N2 hcn C2 dih2
H2 C3 hc N3 hcn C2 dih2
H3 C2 hc N2 hcn C1 dih2
cn = 1.384568
hc = 1.080504
ncn = 120.0000
cnc = 120.0000
hcn = 120.0000
dih1 = 0.0000
dih2 = 180.0000
$end
$rem
JOBTYPE OPT
METHOD MP2
BASIS aug-cc-pVTZ
MEM_TOTAL 128000
MEM_STATIC 2000
$end
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And yielded an energy of -279.850508035596 Hartrees:
Final energy is -279.850508035596
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** OPTIMIZATION CONVERGED **
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Standard Nuclear Orientation (Angstroms)
I Atom X Y Z
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1 N 1.3729488567 0.0000000029 -0.0000000000
2 C 0.6473606386 1.1212615444 -0.0000000000
3 N -0.6864744459 1.1890086148 -0.0000000000
4 C -1.2947212671 -0.0000000025 0.0000000000
5 N -0.6864744404 -1.1890086154 0.0000000000
6 C 0.6473606409 -1.1212615462 0.0000000000
7 H 1.1887311799 2.0589428196 0.0000000000
8 H 1.1887311809 -2.0589428232 0.0000000000
9 H -2.3774623434 0.0000000057 -0.0000000000
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Molecular Point Group D3h NOp = 12
Largest Abelian Subgroup C2v NOp = 4
Nuclear Repulsion Energy = 211.84217054 hartrees
There are 21 alpha and 21 beta electrons
If I use the same geometry as an input to run MP2 in PySCF or adcc with the same basis set, I get energies of -279.954536 Hartrees, roughly 3 eV lower.
Moreover, I performed a scan along one of the normal modes using PySCF and got even lower energies, implying the geometry is not a true minimum eventhough I get all positive frequencies in Q-Chem:
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User input:
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$molecule
READ
$end
$rem
JOBTYPE FREQ
METHOD MP2
BASIS aug-cc-pVTZ
BASIS_LIN_DEP_THRESH 4
MEM_TOTAL 128000
MEM_STATIC 2000
$end
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Requested basis set is aug-cc-pVTZ
There are 111 shells and 345 basis functions
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** **
** VIBRATIONAL ANALYSIS **
** -------------------- **
** **
** VIBRATIONAL FREQUENCIES (CM**-1) AND NORMAL MODES **
** FORCE CONSTANTS (mDYN/ANGSTROM) AND REDUCED MASSES (AMU) **
** INFRARED INTENSITIES (KM/MOL) **
** **
**********************************************************************
Mode: 1 2 3
Frequency: 353.34 353.34 680.06
Force Cnst: 0.2514 0.2514 2.4238
Red. Mass: 3.4183 3.4183 8.8953
IR Active: YES YES YES
IR Intens: 0.000 0.000 16.696
Raman Active: YES YES YES
X Y Z X Y Z X Y Z
N -0.000 -0.000 0.277 0.000 0.000 -0.038 0.178 0.413 0.000
C -0.000 -0.000 -0.142 0.000 -0.000 -0.184 -0.279 0.104 -0.000
N 0.000 0.000 -0.106 -0.000 -0.000 0.258 -0.230 0.005 -0.000
C 0.000 0.000 0.230 0.000 0.000 -0.031 -0.157 -0.349 0.000
N -0.000 -0.000 -0.171 0.000 -0.000 -0.221 0.327 -0.143 -0.000
C -0.000 0.000 -0.088 -0.000 0.000 0.215 0.174 -0.017 0.000
H -0.000 -0.000 -0.447 0.000 -0.000 -0.578 -0.285 -0.190 0.000
H 0.000 0.000 -0.277 -0.000 -0.000 0.677 -0.172 -0.220 -0.000
H 0.000 -0.000 0.725 0.000 0.000 -0.098 -0.255 -0.303 0.000
TransDip 0.000 -0.000 0.000 -0.000 -0.000 -0.000 -0.093 -0.092 0.000
Mode: 4 5 6
Frequency: 680.06 766.00 933.48
Force Cnst: 2.4238 0.6806 0.9724
Red. Mass: 8.8953 1.9688 1.8940
IR Active: YES YES YES
IR Intens: 16.695 27.010 0.959
Raman Active: YES YES YES
X Y Z X Y Z X Y Z
N 0.230 0.006 0.000 -0.000 0.000 -0.127 0.000 -0.000 0.079
C 0.278 0.104 -0.000 0.000 -0.000 0.101 0.000 0.000 -0.139
N -0.178 0.413 0.000 0.000 0.000 -0.127 -0.000 -0.000 0.079
C -0.174 -0.017 0.000 -0.000 -0.000 0.101 0.000 -0.000 -0.139
N -0.327 -0.144 0.000 -0.000 -0.000 -0.127 -0.000 0.000 0.079
C 0.157 -0.349 -0.000 0.000 0.000 0.101 -0.000 -0.000 -0.139
H 0.285 -0.190 -0.000 0.000 -0.000 0.554 -0.000 -0.000 0.555
H 0.255 -0.303 -0.000 0.000 0.000 0.554 0.000 0.000 0.555
H 0.172 -0.220 -0.000 -0.000 -0.000 0.554 -0.000 0.000 0.555
TransDip 0.092 -0.093 -0.000 0.000 -0.000 0.166 -0.000 -0.000 0.031
Mode: 7 8 9
Frequency: 1006.40 1035.26 1035.26
Force Cnst: 8.2435 0.9314 0.9314
Red. Mass: 13.8141 1.4750 1.4750
IR Active: YES YES YES
IR Intens: 0.000 0.000 0.000
Raman Active: YES YES YES
X Y Z X Y Z X Y Z
N -0.285 -0.494 0.000 -0.000 -0.000 0.022 -0.000 0.000 0.025
C -0.056 0.000 0.000 0.000 0.000 -0.162 0.000 -0.000 0.030
N -0.285 0.494 -0.000 0.000 -0.000 0.011 -0.000 -0.000 -0.031
C 0.028 0.048 0.000 -0.000 -0.000 0.107 -0.000 0.000 0.125
N 0.571 0.000 0.000 -0.000 0.000 -0.033 0.000 -0.000 0.006
C 0.028 -0.048 -0.000 0.000 -0.000 0.055 -0.000 -0.000 -0.155
H -0.066 -0.000 0.000 0.000 0.000 0.786 0.000 -0.000 -0.145
H 0.033 -0.057 0.000 0.000 -0.000 -0.267 -0.000 -0.000 0.753
H 0.033 0.057 0.000 -0.000 -0.000 -0.519 -0.000 0.000 -0.608
TransDip -0.000 -0.000 0.000 -0.000 0.000 -0.000 -0.000 -0.000 -0.000
Mode: 10 11 12
Frequency: 1139.63 1194.99 1194.99
Force Cnst: 4.6964 2.0048 2.0048
Red. Mass: 6.1374 2.3828 2.3828
IR Active: YES YES YES
IR Intens: 0.000 0.452 0.452
Raman Active: YES YES YES
X Y Z X Y Z X Y Z
N -0.018 -0.031 0.000 -0.037 -0.109 0.000 0.087 -0.016 -0.000
C 0.392 0.000 -0.000 -0.125 0.117 0.000 -0.125 -0.117 -0.000
N -0.018 0.031 0.000 0.087 0.016 0.000 -0.037 0.109 -0.000
C -0.196 -0.340 -0.000 -0.048 -0.169 0.000 0.161 -0.040 0.000
N 0.036 0.000 0.000 -0.083 0.061 -0.000 -0.083 -0.061 0.000
C -0.196 0.340 -0.000 0.161 0.040 -0.000 -0.048 0.169 -0.000
H 0.422 -0.000 -0.000 -0.135 0.525 -0.000 -0.135 -0.525 0.000
H -0.211 0.365 -0.000 0.646 0.316 0.000 0.074 0.255 0.000
H -0.211 -0.365 -0.000 0.075 -0.255 -0.000 0.645 -0.316 -0.000
TransDip -0.000 -0.000 -0.000 0.015 0.015 -0.000 0.015 -0.015 0.000
Mode: 13 14 15
Frequency: 1245.51 1400.20 1444.32
Force Cnst: 11.3144 1.2983 2.1807
Red. Mass: 12.3790 1.1240 1.7743
IR Active: YES YES YES
IR Intens: 0.000 0.000 44.676
Raman Active: YES YES YES
X Y Z X Y Z X Y Z
N 0.302 -0.175 -0.000 0.040 -0.023 0.000 -0.145 0.069 0.000
C -0.000 0.448 0.000 -0.000 -0.031 -0.000 0.070 0.027 -0.000
N -0.302 -0.175 -0.000 -0.040 -0.023 0.000 -0.013 -0.063 0.000
C 0.388 -0.224 0.000 -0.027 0.016 -0.000 -0.044 -0.004 -0.000
N -0.000 0.349 -0.000 -0.000 0.046 0.000 0.035 0.117 0.000
C -0.388 -0.224 0.000 0.027 0.016 -0.000 0.039 -0.087 -0.000
H -0.000 -0.104 -0.000 -0.000 0.575 0.000 0.077 -0.554 -0.000
H 0.090 0.052 -0.000 -0.498 -0.287 0.000 0.229 0.010 -0.000
H -0.090 0.052 -0.000 0.498 -0.287 0.000 0.641 -0.403 0.000
TransDip 0.000 -0.000 0.000 -0.000 -0.000 0.000 0.151 -0.151 -0.000
Mode: 16 17 18
Frequency: 1444.32 1595.06 1595.06
Force Cnst: 2.1807 8.7712 8.7712
Red. Mass: 1.7743 5.8514 5.8513
IR Active: YES YES YES
IR Intens: 44.676 92.768 92.767
Raman Active: YES YES YES
X Y Z X Y Z X Y Z
N -0.013 0.063 -0.000 -0.202 0.163 -0.000 -0.135 -0.096 0.000
C 0.070 -0.027 0.000 0.087 -0.289 0.000 0.087 0.289 -0.000
N -0.145 -0.069 -0.000 -0.135 0.096 0.000 -0.202 -0.163 -0.000
C 0.039 0.087 0.000 0.326 -0.225 -0.000 0.151 0.051 0.000
N 0.035 -0.117 0.000 -0.110 0.188 -0.000 -0.110 -0.188 0.000
C -0.044 0.004 0.000 0.151 -0.051 0.000 0.325 0.225 -0.000
H 0.077 0.554 0.000 0.089 0.433 -0.000 0.089 -0.433 0.000
H 0.641 0.403 -0.000 -0.077 -0.184 -0.000 -0.528 -0.267 -0.000
H 0.228 -0.010 0.000 -0.528 0.267 0.000 -0.077 0.184 0.000
TransDip 0.151 0.151 0.000 0.218 -0.218 -0.000 0.218 0.218 -0.000
Mode: 19 20 21
Frequency: 3214.95 3214.95 3218.30
Force Cnst: 6.6461 6.6461 6.6938
Red. Mass: 1.0914 1.0914 1.0969
IR Active: YES YES YES
IR Intens: 13.235 13.235 0.000
Raman Active: YES YES YES
X Y Z X Y Z X Y Z
N -0.001 0.001 -0.000 0.000 -0.001 0.000 -0.000 -0.000 0.000
C 0.051 0.001 -0.000 -0.049 0.001 -0.000 -0.052 0.000 -0.000
N -0.000 -0.001 0.000 0.001 0.001 -0.000 -0.000 0.000 0.000
C -0.010 -0.014 0.000 -0.034 -0.060 0.000 0.026 0.045 -0.000
N 0.000 0.001 0.000 -0.000 0.001 0.000 0.000 0.000 0.000
C 0.034 -0.059 -0.000 0.011 -0.016 0.000 0.026 -0.045 -0.000
H -0.585 -0.000 0.000 0.565 -0.000 0.000 0.575 0.000 0.000
H -0.391 0.677 0.000 -0.112 0.194 -0.000 -0.288 0.498 0.000
H 0.099 0.170 -0.000 0.394 0.683 -0.000 -0.288 -0.498 0.000
TransDip 0.084 -0.081 0.000 -0.081 -0.084 -0.000 0.000 -0.000 0.000
Does someone have any clue on what is going on?
Thank you in advance for any help!