<div dir="ltr">Dear All,<div><br></div><div><div>I'm doing vibrational analysis in order to validate some of the saddle points achieved from the NEB calculations. I have a system consist of impinging molecules on the metal surface, so for doing vib. analysis, I have fixed all the metal slab's atoms and only tried to do the calculation for the molecules adsorbed on the surface (I don't know how valid this is! Any thoughts?).</div><div>The problem is, even though the keyword FULLY_PERIODIC is set to False by default for removing the rotational frequencies, I still get three imaginary frequencies which I have no clue where they are coming from. Do you have any idea about the source of these "extra" imaginary frequencies? Or in another words, what is your best suggested strategy to get a single imaginary frequency for the validation of the results coming from NEB calculations?</div><div><br></div><div>I have attached my input, (a part of output) and the coordinate file of the TS. Your advice or suggestion would be much appreciated.</div><div><br></div><div>Kind regards,</div><div><br></div><div>Jacob</div><div><br></div><div><div> VIB| NORMAL MODES - CARTESIAN DISPLACEMENTS</div><div> VIB|</div><div> VIB| 1 2 3</div><div> VIB|Frequency (cm^-1) <span style="background-color: rgb(255, 255, 0);">-627.437013</span> <span style="background-color: rgb(255, 255, 0);"> -370.258287 </span> <span style="background-color: rgb(255, 255, 0);">-12.385518</span></div><div> VIB|Intensities 0.000000 0.000000 0.000000</div><div> VIB|Red.Masses (a.u.) 2.780368 1.414776 3.913531</div><div> VIB|Frc consts (a.u.) -0.001103 -0.000068 -0.000000</div><div> ATOM EL X Y Z X Y Z X Y Z</div><div> 65 N 0.07 0.13 -0.15 0.14 -0.05 0.07 -0.13 0.37 0.13</div><div> 66 C -0.03 -0.24 0.22 -0.01 0.07 -0.05 0.01 0.24 -0.02</div><div> 67 H -0.41 0.72 -0.16 -0.95 0.05 -0.03 -0.17 0.34 -0.06</div><div> 68 H 0.15 0.17 -0.15 0.14 -0.11 0.09 0.38 0.52 0.28</div><div> 69 H -0.04 -0.19 -0.17 0.14 -0.05 0.03 -0.22 -0.16 -0.25</div><div><br></div><div><br></div><div> VIB| 4 5 6</div><div> VIB|Frequency (cm^-1) 94.311628 142.307646 224.156404</div><div> VIB|Intensities 0.000000 0.000000 0.000000</div><div> VIB|Red.Masses (a.u.) 4.349457 2.189311 1.433603</div><div> VIB|Frc consts (a.u.) 0.000001 0.000002 0.000009</div><div> ATOM EL X Y Z X Y Z X Y Z</div><div> 65 N 0.14 0.08 -0.38 0.23 0.12 0.14 0.13 -0.02 -0.02</div><div> 66 C 0.02 0.31 -0.08 0.03 -0.06 0.02 0.13 0.02 -0.01</div><div> 67 H 0.10 0.18 -0.03 0.44 0.06 -0.02 0.37 -0.09 0.03</div><div> 68 H -0.31 -0.15 -0.47 -0.12 0.20 -0.02 0.61 -0.02 0.17</div><div> 69 H 0.22 0.53 -0.10 0.32 0.59 0.45 0.09 -0.45 -0.45</div><div><br></div><div><br></div><div> VIB| 7 8 9</div><div> VIB|Frequency (cm^-1) 421.227384 449.047513 749.374099</div><div> VIB|Intensities 0.000000 0.000000 0.000000</div><div> VIB|Red.Masses (a.u.) 3.868163 5.072223 1.257520</div><div> VIB|Frc consts (a.u.) 0.000312 0.000528 0.001015</div><div> ATOM EL X Y Z X Y Z X Y Z</div><div> 65 N 0.06 -0.05 0.04 -0.02 -0.10 0.08 -0.08 -0.09 0.01</div><div> 66 C -0.45 0.12 0.17 0.24 0.25 0.48 0.07 -0.01 0.01</div><div> 67 H 0.39 -0.02 0.22 -0.02 0.15 0.52 -0.08 0.27 -0.11</div><div> 68 H 0.41 -0.21 0.24 -0.35 -0.30 0.03 0.37 0.25 0.08</div><div> 69 H 0.24 0.14 -0.44 -0.08 -0.08 0.34 0.27 0.72 -0.31</div><div><br></div><div><br></div><div> VIB| 10 11 12</div><div> VIB|Frequency (cm^-1) 854.933502 940.779054 1487.032716</div><div> VIB|Intensities 0.000000 0.000000 0.000000</div><div> VIB|Red.Masses (a.u.) 1.261018 1.071511 1.088996</div><div> VIB|Frc consts (a.u.) 0.001725 0.002149 0.013633</div><div> ATOM EL X Y Z X Y Z X Y Z</div><div> 65 N -0.02 0.11 -0.01 -0.01 -0.01 0.05 0.03 -0.02 0.07</div><div> 66 C 0.04 -0.07 0.03 0.01 0.01 -0.05 0.00 0.00 0.00</div><div> 67 H -0.18 -0.49 0.23 0.18 0.63 -0.30 -0.01 -0.00 -0.00</div><div> 68 H -0.10 -0.57 0.23 -0.21 -0.61 0.20 -0.55 0.29 -0.36</div><div> 69 H 0.12 0.31 -0.39 0.01 -0.05 -0.12 0.12 -0.11 -0.67</div><div><br></div><div><br></div><div> VIB| 13 14 15</div><div> VIB|Frequency (cm^-1) 3078.134845 3178.790354 3420.829077</div><div> VIB|Intensities 0.000000 0.000000 0.000000</div><div> VIB|Red.Masses (a.u.) 1.083814 1.061101 1.079557</div><div> VIB|Frc consts (a.u.) 0.249102 0.277381 0.378480</div><div> ATOM EL X Y Z X Y Z X Y Z</div><div> 65 N -0.00 -0.00 -0.00 0.01 -0.02 -0.06 -0.07 0.03 0.00</div><div> 66 C -0.00 -0.03 -0.08 -0.00 -0.00 0.00 0.00 -0.00 0.00</div><div> 67 H 0.01 0.38 0.92 0.00 -0.00 -0.02 -0.00 -0.00 -0.01</div><div> 68 H -0.00 0.02 0.01 -0.39 0.35 0.82 0.05 -0.07 -0.19</div><div> 69 H 0.02 -0.01 0.00 0.21 -0.09 0.00 0.91 -0.30 0.18</div><div><br></div><div><br></div></div><div></div></div></div>