<div dir="ltr">Roughly, yes. If it was CI, the square of the coefficients make up the many-body wavefunction. In TD-DFT it is analogous, but not formally the same but provides a guide as to which states contribute to a transition.<div><br></div><div>Matt <br><br>On Thursday, June 20, 2019 at 6:25:53 AM UTC+1, Fan Tian wrote:<blockquote class="gmail_quote" style="margin: 0;margin-left: 0.8ex;border-left: 1px #ccc solid;padding-left: 1ex;"><div dir="ltr"><div><br></div><div>Dear all, <br></div><div>I performed TDDFPT calculation in CP2K to generate the adsorption spectra of a molecular. When i activated the TDDFPT module by the controls in &PROPERITIES section<code>, i can obtain the following printout which is useful to the plot. <br></code></div><div><code><br></code></div><div> R-TDDFPT states of multiplicity 1<br><br>          State     Excitation      Transition dipole (a.u.)        Oscillator<br>          number    energy (eV)       x         y         z       strength (a.u.)<br>         ------------------------------<wbr>------------------------------<wbr>------------<br> TDDFPT|       1        1.23854      0.0001    0.0001   -0.0008        0.00000<br> TDDFPT|       2        1.32924      0.0014    0.0015    0.0074        0.00000<br> TDDFPT|       3        1.60705     -0.0015    0.0036    1.2125        0.05788<br> TDDFPT|       4        1.71778      0.0242    0.0312    0.0803        0.00034<br> TDDFPT|       5        1.72009     -0.0395   -0.0408    0.0618        0.00030</div><div>..............................<wbr>..............................<wbr>..............................<wbr>.................</div><div><br></div><div><br></div><div>Excitation analysis<br><br>   State        Occupied         Virtual        Excitation<br>   number        orbital         orbital        amplitude<br> -----------------------------<wbr>----------------------------<br>        1<br>                  990             991            -0.997314<br>        2<br>                  989             991            -0.996581<br>        3<br>                  988             991             0.992140<br>        4<br>                  990             992             0.991598<br>                  990             993             0.111758<br>                  990             994            -0.050726<br>        5</div><div>..............................<wbr>..............................<wbr>...............</div><div><br></div><div><span><span><span>I would like to know what is the 
excitation amplitude?  is it the same to elecitation coefficient that can be used to derive the contribution of the transition to the excitaion state?  <br></span></span></span></div><div><br><span><span><span></span></span></span></div><br><span><span><span></span></span></span><code></code><code style="background-color:rgb(255,255,255);border-bottom-color:rgb(0,0,0);border-bottom-left-radius:2px;border-bottom-right-radius:2px;border-bottom-style:none;border-bottom-width:0px;border-left-color:rgb(0,0,0);border-left-style:none;border-left-width:0px;border-right-color:rgb(0,0,0);border-right-style:none;border-right-width:0px;border-top-color:rgb(0,0,0);border-top-left-radius:2px;border-top-right-radius:2px;border-top-style:none;border-top-width:0px;color:rgb(0,0,0);font-family:monospace;font-size:20.8px;font-style:normal;font-variant:normal;font-weight:400;letter-spacing:normal;padding-bottom:0px;padding-left:0px;padding-right:0px;padding-top:0px;text-align:left;text-decoration:none;text-indent:0px;text-transform:none;white-space:pre-wrap;word-spacing:0px"></code><span style="display:inline!important;float:none;background-color:transparent;color:rgb(0,0,0);font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-size:20.8px;font-style:normal;font-variant:normal;font-weight:400;letter-spacing:normal;text-align:left;text-decoration:none;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"></span><span style="display:inline!important;float:none;background-color:transparent;color:rgb(0,0,0);font-family:"Helvetica Neue",Helvetica,Arial,sans-serif;font-size:20.8px;font-style:normal;font-variant:normal;font-weight:400;letter-spacing:normal;text-align:left;text-decoration:none;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px"></span></div></blockquote></div></div>