We have performed quantum-chemical ab initio in various basis sets at the Hartree-Fock andB3LYP levels for Adenine and Thymine with the program GAUSSIAN98. The Dipole,Quadrupole, Octapole and Hexadecapole moments and primitive in nine basis sets for thesemolecules are presented. The most stabilized forms of these molecules are observed in 6-311++G** basis set. We have evaluated coefficient hybr...

We report a highly correlated multireference configuration interaction calculation of the near-equilibrium potential energy surface of ozone using a large correlation consistent basis set. Three-dimensional analytical expressions are obtained for the potential energy and dipole moment functions using least-squares fits to ab initio points near the C2v equilibrium geometry. Low-lying vibrational...

An interaction potential at different orientation for the CH4 and CO2 complex was derived at theB3LYP level of theory and 6-31+G* basis sets. The potential energy surface was computed on somemolecular geometries. The complete basis set limit of the interaction energies were fitted to wellknownanalytical functions. To determine the second virial coefficients B, U(r) is used to obtain themodel’s ...

In this study, we theoretically investigated Methyl hydrazinecarbodithioate by quantum chemical calculations for geometry optimization, vibration frequencies, and electronic structure parameters. The geometry optimization by DFT, ab initio MP2 method and the frequency calculation by DFT method was performed at the highest available Pople style 6-311G++(3df,3pd) basis set level. The semi-emp...

nowadays nmr spectroscopy becomes a powerful tool in chemistry because of the nmr chemical shifts. hartree–fock theory and the gauge-including atomic orbital (giao) methods are used in the calculation of 29si nmr chemical shifts of various silicate species in the silicate solution as initial components for zeolite synthesis both in gas and solution phase. calculations have been performed at geo...

Potential energy surfaces form a central concept in the application of electronic structure methods to the study of molecular structures, properties, and reactivities. Recent advances in tools for exploring potential energy surfaces are surveyed. Methods for geometry optimization of equilibrium structures, searching for transition states, following reaction paths and ab initio molecular dynamic...

an interaction potential at different orientation for the ch4 and co2 complex was derived at theb3lyp level of theory and 6-31+g* basis sets. the potential energy surface was computed on somemolecular geometries. the complete basis set limit of the interaction energies were fitted to wellknownanalytical functions. to determine the second virial coefficients b, u(r) is used to obtain themodel’s ...

we have performed quantum-chemical ab initio in various basis sets at the hartree-fock andb3lyp levels for adenine and thymine with the program gaussian98. the dipole,quadrupole, octapole and hexadecapole moments and primitive in nine basis sets for thesemolecules are presented. the most stabilized forms of these molecules are observed in 6-311++g** basis set. we have evaluated coefficient hybr...