Real-Space Ab-Initio Calculations on the Basis of Spectral Element Method

Gaussian Basis Sets for High - Quality ab Initio Calculations 3029

Different types of Gaussian basis sets for accurate LCAO calculations are discussed. For calculations designed to recover a substantial portion of the correlation energy, we suggest the use of basis sets comprising natural orbitals from correlated calculations on the atoms. These basis sets have proven to be very efficient in accounting for large fractions of the molecular correlation energy. F...

pKa predictions of some aniline derivatives by ab initio calculations

: In this work, different levels of theory containing HF, B3LYP, and MP2 with different basis sets such as 6-31G, 6-31G*, 6-311G, 6-311+G, 6-31+G*, 6-31+G are used to predict relative acidity constants of some aniline derivatives. Three different kinds of radii containing UAHF, Bondi, and Pauling are used to study how cavity forms change acidity constants. In all cases, DPCM model is used to si...

Ab Initio Calculations on Some C3SiH4 Isomers

Ab initio calculations of the hydrogen bond

Recent x-ray Compton scattering experiments in ice have provided useful information about the quantum nature of the interaction between H2O monomers. The hydrogen bond is characterized by a certain amount of charge transfer which could be determined in a Compton experiment. We use ab initio simulations to investigate the hydrogen bond in H2O structures by calculating the Compton profile and rel...

Ab initio Calculations SWNTs and Investigation of Interaction Atoms of Oxygen with that by Computational Calculations

In this work, theoretical investigations on carbon nanotube with oxygen atom have been carried out by firstprinciplescalculations and density functional theory and hartree fock theory in 3-216 and 6-316 basis sets. Theinteraction energy of the oxygen atom to a CNT is calculated. The effects of this substitutions have beeninvestigated on the during transplantation (10,0) single-walled carbon nan...