Does anyone know how to freeze or fix a specific dihedral in MOPAC? In Gaussian09, you can use the specific command "D 1 2 3 4 F" to fix a specific dihedral. I cannot find an analogous command for MOPAC because not all the dihedrals are in the z-matrix. Thanks!
Hi David,
To fix dihedrals, you should set 0 for optimization of dihedrals:
Check the following link about "To freeze a bond-length, angle, or dihedral":
http://openmopac.net/manual/trouble_shooting.html
Dear Friend,
To freeze the dihedral angle in the input generated by MOPAC, you should replace the number 1 stands before the value of the targeted angle with the number 0.
Hoping this will be helpful,
Rafik
I am interested in fixing the angles of my peptide backbone but the dihedrals defined in the z-matrix can be anything. Many of the dihedrals that I am interested in fixing for the calculation are not found in the z-matrix and don't have a 1 or a 0 that I can change.
- Badges
- Science topic