Rotation of the Conical Intersection

It is not necessary to rotate the conical intersection: MCTDH will do this automatically. However, the program needs to be told (via a question in the generator) by how much to rotate the conical intersection.

The three angles required can be found using an EXCEL spreadsheet.

Media:Cis-butadiene_XQ-transform1.xls

The EXCEL spreadsheet contains different coloured boxes:

1) BLUE: data about the ground state minimum (provided by the user)

2) RED: data about the conical intersection (provided by the user)

3) YELLOW: Euler angles (calculated by the spreadsheet)

4) GREEN: the frequency-mass-weighted normal coordinates (calculated by the spreadsheet)

5) ORANGE: the geometry of the rotated conical Intersection (calculated by the spreadsheet)

To use the EXCEL spreadsheet, you simply need to:

1) Input the ground state minimum and conical intersection geometries, and the ground state minimum vibrational information

Ground state minimum structure

BLUE BOX From C2-E2 to C11-E11

Conical Intersection structure

RED BOX From C13-E13 to C22-E22

Ground state minimum normal modes of vibration

BLUE BOX Z2-AW2 to Z31-AW31

Ground state minimum frequencies

BLUE BOX From L10 to L33

2) Run the solver optimization

set the three Euler angles in the yellow boxes K3, K4 and K5 to zero.
Select: Tools > Solver
Minimise M7

Need to explain here what to do when this doesn't work and what results you should expect

3) Note the three angles in K3, K4 and K5

These three angles are required as part of the input for MCTDH. In this case they are 180.000, 0.000 and 90.000 (in that order).