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Resgrp:comp-photo-dyn/mctdh90.56dv Fulvene Tutorial/rotation

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Rotation of the Conical Intersection

Dynamics are performed in internal coordinates, so it is necessary to remove any translations or rotational components in the starting and conical intersection reference geometries. To this end it is necessary to perform a rotation/displacement of the conical intersection geometry. Although MCTDH (DD-vMCG) will do this automatically, the program needs to be told (via a question in the generator) by how much to rotate the conical intersection. We will perform the rotation beforehand providing the {0,0,0} tuple to the program. This is done using the dd_rotation method.

dd_rotation method

Note:dd_rotation program only works with the output of gaussian development version gdvh01.

Create a new directory for the rotation and populate it with two files, which must be named start.log and coin.dat, and the dd_rotation program.

  • start.log is the gaussian output file from the high precision vibrational modes of the ground state with state averaged orbitals (with atom types rather than numbers)

Media:Start.log

  • coin.dat is the conical intersection reference geometry in xyz format. (i.e. it is the last geometry printed out in Media:Fulv_ci.log )

Media:Coin.dat

  • The dd_rotation program, written by David, reads the start.log and coin.dat files and will output a file called coin.out which is a xyz with the rotated conical intersection geometry. The program also outputs to stdout the relevant rotation angles.

Media:Dd_rotation_v2.x

The rotated geometry should be visually checked for consistency against the starting geometry.

Taking the rotated geometry (from coin.out) it is necessary to perform a new conical intersection optimization to obtain the orbitals and branching space coordinates. (this time without the keyword opt=tight)

Media:Coin.gjf

Media:Coin.log


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