Finite size scaling with gaussian basis sets

Autor: Winton Moy, Sabre Kais, Pablo Serra
Rok vydání: 2008
Předmět:
Zdroj: Molecular Physics. 106:203-212
ISSN: 1362-3028
0026-8976
DOI: 10.1080/00268970701528714
Popis: We combined finite size scaling method with the well-developed electronic structure methods, such as ab initio and density functional methods, to provide a systematic procedure for obtaining quantum critical parameters for atoms and molecules using Gaussian basis sets. The finite size scaling method is based on taking the number of elements in a complete basis set as the size of the system, to calculate the critical parameters for a given quantum system. We present results for the Yukawa potential and helium-like systems by expanding the wave function with a Gaussian basis. The finite size scaling approach was then used with the ab initio methods to find the critical parameters of two-electron atoms. The critical values of λc and α were found to be 1.0578 and 1.0711 respectively using Moller–Plesset (MP2) level of theory. We then applied configuration interaction single and doubles excitation (CISD) to the helium system to improve upon the results. The critical parameters at the CISD level of theory were ...
Databáze: OpenAIRE