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--- exercises:2016_summer_school:excited [2016/08/26 07:22] – created mwatkins
+++ exercises:2016_summer_school:excited [2020/08/21 10:15] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
 ===== Excited states =====
-Input file for real time propagation of formaldehyde
+Input file for real time propagation of formaldehyde.
+This file will excite the formaldehyde using an impulse (''delta kick'') then propagate the system in time.
+The file ch2o_pbe_rtp-output-moments.dat should contain the system dipole moment at each time step.
+By extracting the z component of this moment and taking a discrete fourier transform of it (xmgrace maybe) you should be able to obtain the optical absorption spectrum of formaldehyde at PBE level.
 <code cp2k input.inp>
@@ Line 104: / Line 110: @@
   &END MD
 &END MOTION
+</code>
+Here is an input that calculates the first five excited states of formaldehyde using TDDFPT instead. The energies should be the same as for RTP.
+//Note that this needs a very up to date CP2K executable to work version > r17219//
+<code cp2k input_tddfpt.inp>
+&GLOBAL
+  PROJECT ch2o_pbe_rks_s_tddfpt
+  RUN_TYPE energy
+  PRINT_LEVEL low
+&END GLOBAL
+&FORCE_EVAL
+  METHOD Quickstep
+  &PROPERTIES
+    &TDDFPT
+       NSTATES      5
+       MAX_ITER    10
+       CONVERGENCE [eV] 1.0e-3
+    &END TDDFPT
+  &END PROPERTIES
+  &DFT
+    BASIS_SET_FILE_NAME GTH_BASIS_SETS
+    POTENTIAL_FILE_NAME POTENTIAL
+    &MGRID
+      CUTOFF 400
+    &END MGRID
+    &QS
+      METHOD gpw
+    &END QS
+    &SCF
+      MAX_SCF   30
+      EPS_SCF   1e-7
+      SCF_GUESS atomic
+    &END SCF
+    &POISSON
+       PERIODIC none
+       POISSON_SOLVER wavelet
+    &END POISSON
+    &XC
+      &XC_FUNCTIONAL pbe
+      &END XC_FUNCTIONAL
+      &XC_GRID
+        XC_DERIV SPLINE2_SMOOTH
+      &END XC_GRID
+    &END XC
+  &END DFT
+  &SUBSYS
+    &TOPOLOGY
+       &CENTER_COORDINATES
+       &END CENTER_COORDINATES
+    &END TOPOLOGY
+    &CELL
+      ABC 9.0 9.0 9.0
+      PERIODIC NONE
+    &END CELL
+    &COORD
+  O         0.094933   -0.000368    0.895642
+  C        -0.031077   -0.000121   -0.307326
+  H        -0.090437    0.947608   -0.895642
+  H        -0.094933   -0.947608   -0.895562
+    &END COORD
+    &KIND O
+      BASIS_SET aug-TZV2P-GTH
+      POTENTIAL GTH-PBE-q6
+    &END KIND
+    &KIND C
+      BASIS_SET aug-TZV2P-GTH
+      POTENTIAL GTH-PBE-q4
+    &END KIND
+    &KIND H
+      BASIS_SET aug-TZV2P-GTH
+      POTENTIAL GTH-PBE-q1
+    &END KIND
+  &END SUBSYS
+&END FORCE_EVAL
 </code>