Ab initio CHF-GIAO13C nuclear shielding calculations on carbohydrates

Ab initio calculations of Co shielding in model complexes

Recent ab initio calculations of cobalt NMR shielding show that DFT-GIAO calculations using hybrid functionals are found to reproduce experimental values well. This method is used to calculate the variation of the cobalt NMR shielding tensor of sqaure pyramidal nitrosyl complexes with respect to the CoNO geometry and to differing basal ligands. The isotropic shielding is shown to have a large n...

An Ab initio and chemical shielding tensors calculations for Nucleotide 5’-Monophosphates in the Gas phase

Structural and magnetic properties of purine and pyrimidine nucleotides (CMP, UMP, dTMP, AMP, GMP, IMP) were studied at different levels of ab initio molecular orbital theory. These calculations were performed at the hartree-fock level and density functional B3LYP methods. Geometries were fully optimized by following Cs symmetry restrictions. The standard 6-31G** basis set which includes polari...

Accelerating Ab Initio Nuclear Physics Calculations with GPUs

This paper describes some applications of GPU acceleration in ab initio nuclear structure calculations. Specifically, we discuss GPU acceleration of the software package MFDn, a parallel nuclear structure eigensolver. We modify the matrix construction stage to run partly on the GPU. On the Titan supercomputer at the Oak Ridge Leadership Computing Facility, this produces a speedup of approximate...

Utilizing Symmetry Coupling Schemes in Ab Initio Nuclear Structure Calculations

We report on ab initio no-core shell model calculations in a symmetryadapted SU(3)-based coupling scheme that demonstrate that collective modes in p-shell nuclei emerge from first principles. The low-lying states of Li, He, Be, B, C, and O, are shown to exhibit orderly patterns that favor spatial configurations with strong quadrupole deformation and complementary low intrinsic spin values, a pi...

Ab Initio Calculations on Some C3SiH4 Isomers