Resgrp:comp-photo-dyn/mctdh90.31dv/rotation
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: the cartesian coordinates of the ground state minimum (provided by the user)
2) RED: the cartesian coordinates of 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
Ground state minimum structure
- Paste the cartesian coordinates of the ground state minimum (in start.log) in the BLUE BOX (C2-E2 to C11-E11).
Conical Intersection structure
- Paste the cartesian coordinates of the conical intersection (in coin.log) in the RED BOX (C13-E13 to C22-E22).
Ground state minimum normal modes of vibration
- Paste normal modes of the ground state minimum (in start.log) in the BLUE BOX (Z2-AW2 to Z31-AW31).
Ground state minimum frequencies
- Paste the frequencies of the ground state minimum (in start.log) in the BLUE BOX (L10 to L33).
2) Run the solver optimization
- set the three Euler angles in the yellow boxes "Angles deg" (K2, K3 and K4) to zero.
- select: Tools > Solver
- minimise "Mw vib. norm" (M7)
The desired solution is one where "Mw norm" (M6) and "Mw vib. norm" (M7) are equal; "Mw rot. Norm" (M8) is zero; and the three angles (K2-K4) are minimised. If minimising "Mw vib. norm" (M7) does not achieve this, try solving for "Mw rot. Norm" (M8) equal to zero or minimising "Mw norm" (M6) (or combinations of these).
There is more than one possible solution! The best choice is the one where the three angles are smallest (and all the other criteria are satisfied).
3) Note the three angles in degrees (K2, K3 and K4)
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).