COULOMB PARAMETERS IN SIMPLE HUCKEL AND OMEGA TECHNIQUE MOLECULAR ORBITAL METHODS

A Generalized Omega-Technique for Molecular Orbital Calculations

A der ivat ion of the omega-l ike m e t h o d s t o ca lcula te electronic molecular s t ruc tu res is given. The der iva t ion is based on the Har t r ee -Fock formal i sm a n d shows in a n a t u r a l way how t h e omega-l ike m e t h o d s follows t h r o u g h t h e re tent ion of cer ta in two-electron repulsion in tegra ls a n d the neglection of o ther ones. A general ized omegatechn iq...

Coulomb-corrected molecular orbital tomography of nitrogen

High-order harmonic generation (HHG) from aligned molecules has provided a promising way to probe the molecular orbital with an Ångström resolution. This method, usually called molecular orbital tomography (MOT) replies on a simple assumption of the plane-wave approximation (PW), which has long been questioned due to that PW approximation is known to be valid in the keV energy region. However, ...

Molecular orbital methods in organic chemistry

A simple technique for removal of orbital tumors: transmaxillary approach.

In this article, we present the case of a 43-year-old female with a tumor of the orbital base. Computed tomography revealed a well-defined contrast enhancing cavernous hemangioma behind the left bulbus oculi. The surgical resection was performed by transmaxillary approach to the orbit. No clinical complications were observed during three-month follow-up following surgery.

Extended Huckel Theory and Molecular Hartree-fock Scf Theory.

In the past several years a wide variety of molecules has been studied by means of the extended Htickel theory, which explicitly includes all overlaps between atomic orbitals and systematic guesses for the elements of the Hamiltonian matrix.1 These studies, in spite of their very approximate nature, have yielded a wealth of chemical information in terms of eigenvalues and eigenvectors: charge d...