Dihedral angle • The angle created by two intersecting planes
Importance of dihedral angle Conformation
Molecule of Interest C14H20N2
1. Change in dihedral angle Minimal basis HF 139.95
6-21 G HF 120.60
6-31G* HF 116.34
6-31G** HF 116.11
6-31+G* HF 118.50
Comparison Dihedral angle Basis set
116.11 139.95 Minimal basis HF 6-31G**
HOMO LUMO Minimal basis 6-31G**
Density distribution on HOMO and LUMO HOMO LUMO Minimal basis 6-31G**
2.HOMO LUMO ENERGY GAP Energy Gap (eV) Dihedral Angle
Conclusions 1. Dihedral angle became defined with better basis sets. 2. Change in dihedral angle effects the HOMO - LUMO gap of the molecule.
Reference 1.http://www.structuralbioinformatics.com/chapter7.shtml 2.http://www.cartage.org.lb/en/themes/Sciences/Chemistry/Org anicchemistry/Common/Common.htm. 3. Organic Chemistry, William H. Brown, Christopher S., Foote Brent L. Iverson 4. A brief guide to Molecular Mechanics and Quantum Chemical calculations , warren J. Hehre, Jianguo Yu, Philip E. Klunzinger, Liang Lou.