Approximate self-consistent field calculations of molecular potential surfaces

• Main Author: Yun, Chang Sop
• Other Authors: Tolles, William M.
• Language: en_US
• Published: Monterey, California. U.S. Naval Postgraduate School 2012
• Online Access: http://hdl.handle.net/10945/11696

Approved for public release, distribution is unlimited === The Approximate Self-Consistent Field Molecular Orbital Theory (ASCFT) with complete neglect of differential overlap (CNDO) has been applied to the calculation of electronic structure for several selected molecules in this text . The theory leads to calculated equilibrium geometry configurations and the barrier to internal rotation of ethane, inversion barrier of armnonia and the barrier for cis to trans conversion for difluorodiazine. These results are in reasonable agreement with experimental. values in most cases. The stretching force constants are higher than experimental values by a factor of approximately two. The orbital energy levels for ammonia and for oxygen difluoride as a function of bond angles were in reasonable agreement with the full LCAO-SCF Calculations. A variation of parameters to find a new set of parameters- was attempted with unsuccessful results. The Extended Huckel Theory (EHT) can be applied to aliphatic hydrocarbons but its application to non-hydrocarbon molecules is quite limited.