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| Author(s): |
Tiago Quevedo Teodoro
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC/BT) |
| Defense date: | 2016-09-28 |
| Examining board members: |
Roberto Luiz Andrade Haiduke;
Alejandro Lopez Castillo
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| Advisor: | Roberto Luiz Andrade Haiduke |
| Abstract | |
Pioneering studies with ab initio calculations from the 1970s gave rise to the computational relativistic quantum chemistry field. Since then, also due to the exponential growth in computational resources, the application of relativistic Hamiltonians in theoretical chemistry calculations has become more common. However, the development of basis sets to be used in such calculations have presented its struggles. After decades, technical limitations, such as the variational prolapse issue still persist. Hence, the aim of the present thesis was the development of efficient relativistic Gaussian basis sets to be applied in correlated ab initio calculations. In order to do that, a polynomial version of the generator coordinate Dirac-Fock method has been applied to obtain variationally optimized primitive sets that are free of prolapse. Correlating/polarization functions, as well as diffuse ones, were added to these sets in a quadruple-ζ type of increment. Such functions were chosen by means of the Dirac-Coulomb multi-reference configuration interaction treatment. Molecular calculations of fundamental properties have attested the high quality of the designated RPF-4Z sets in comparison with other well-known relativistic sets. Furthermore, nuclear electric quadrupole moments of bismuth and potassium isotopes and a potential energy curve of the radium dimer were also analyzed. Since these generated sets are as accurate as commonly used relativistic quadruple-ζ sets already available, but with the advantage of a reduced computational demand, the RPF-4Z sets are expected to represent a great advance in the field. (AU) | |
| FAPESP's process: | 12/22143-5 - Development of polarized relativistic Gaussian-type basis sets and relativistic applications |
| Grantee: | Tiago Quevedo Teodoro |
| Support Opportunities: | Scholarships in Brazil - Doctorate |