Duli C. Jain

A Theoretical Study of LiHe+ n , NaHe+ n , and MgHe+ n Complexes, with n=1, 2, 3, 4

The LiHe+n, the NaHe+n, and the MgHe+n complexes with n=1, 2, 3, 4 were studied using ab initio calculations with the MP2/6-311+G(3df, 3pd) method. The complexes are found to be stable. For the n=1 complexes, previous results were available and the calculations performed are in good agreement with those results. This lends credibility to the results obtained for the complexes with higher n.

An ab initio study of ammonia-hydrocarbon complexes

Abstract Complexes formed between NH 3 and such hydrocarbons as ethane, ethylene, benzene and fluorobenzene are studied with ab initio methods, using 6-31G * and 6-31G basis sets. It is found that the most stable complexes in all cases are the ones formed by a hydrogen bond between the nitrogen and a hydrogen of the hydrocarbon, as well as between the fluorine of the fluorobenzene and a hydrogen of the NH 3 .

Quantum Chemical Studies Employing an Ab Initio Combination Approach on the Binding of the Bis-Benzimidazole Hoechst 33258 to the Minor Groove of DNA

Ab initio calculations (Hartree-Fock) using the 3-21G and the STO-3G Gaussian basis sets were performed on the sequence selective minor groove binding bis-benzimidazole Hoechst 33258. Geometry optimized conformations, energies and distribution of electrostatic charges within the molecule were derived. The binding of the optimized conformations of the drug to both alternating and non-alternating (AT)n sequences was studied.

An Ab Initio Study of the Complexes Formed by the Positive Acetylene Ion with the Hydrogen and Nitrogen Molecules and the Argon Atom

The complexes formed by the positive acetylene ion with the hydrogen molecule, the nitrogen molecule, and the argon atom are investigated with ab initio calculations using the 6-311G** and the 6-31+G(2df,2pd) basis sets. MP2/6-311G** energies and optimum geometries are obtained, as well as single-point MP3, MP4, and QCISD(T) energies with the MP2/6-311G** optimized geometries. Single-point calculations are performed with the 6-31+G(2df,2pd) basis set at MP2/6-311G** optimized geometries.

An Ab Initio Study of C2H2.H2, C2H2.N2, and C2H2.Ar Complexes

Ab initio calculations at the post Hartree–Fock level were performed on complexes of acetylene with hydrogen, nitrogen, and argon. Total energies, optimum geometries, and binding energies were calculated, using the 6-311G** and the 6-31+G(2df,2pd) basis sets. Calculations showed the complexes to be more stable than the separate entities, with the exception of the acetylene–hydrogen complex.

Ab initio studies of some negative complexes of lithium compounds

Abstract Negative complexes of the form [X---Li---Y] − , where X and Y are OH − , NH − 2 and CH − 3 , are studied using the 6–31 + G* basis set. It is found that the most stable complexes feature the lithium cation shared by the two anions.

Theoretical Studies Using an Ab Initio and Molecular Modelling Combination Method on the Binding of Sequence Recognition Altered Bis-Benzimidazoles to the Minor Groove of DNA

Ab initio calculations (Hartree-Fock) using the 3-21G and the STO-3G Gaussian basis sets were performed on synthetic analogues of the minor groove binding bis-benzimidazole Hoechst 33258 designed to exhibit altered sequence recognition. Geometry optimized conformations, energies and distribution of electrostatic charges within the molecule were derived. The binding of the optimized conformations of the drug to both alternating and non-alternating (AT)n and (GC)n sequences were studied.

An ab initio study of the attack of a nitrosoiminium ion on formamide as a model for DNA bases

SummaryThe attack of a nitrosoiminium ion (an intermediate formed in the decomposition of nitrosamines) on formamide is studied by ab initio methods at Hartree-Fock level and with the Moller-Plesset (MP2) method. The results show that the complex thus formed is lower in energy than the reactants.

Ab initio studies of the NF2Li and NHLi2 dimers

Abstract In an attempt to elucidate the nature of the dimeric bond in NLiX 2 compounds, ab initio calculations with 3-21G and 6-31G* basis sets are performed on NF 2 Li and NHLi 2 . The former exhibits an asymmetric structure, with a binding energy about half that of the NH 2 Li dimer, while the latter features C 2v symmetry and a binding energy approximately the same as that of (NH 2 Li) 2 . It is concluded that the dimerization occurs via a contribution of covalent bonding.