The article discusses the Hy-CI method, a hybrid approach combining the high precision of Hy methods with configuration interaction techniques to calculate atomic properties with unprecedented accuracy. This method has been successfully applied to two-electron systems like helium, achieving results accurate to 20 decimal digits.
The Hy-CI method’s importance lies in its ability to handle larger basis sets and more complex systems while maintaining high precision. It has been extended to three and four-electron systems, enabling calculations of properties like ionization potentials, polarizabilities, and transition probabilities.
Recent developments include the use of parallel processing and extended precision arithmetic to handle the increased computational demands. The method has been generalized to exponentially correlated Hy-CI, allowing for even more accurate calculations of excited states and oscillator strengths.
The article highlights several key publications demonstrating the method’s effectiveness across various atomic systems and properties. The Hy-CI method represents a significant advancement in computational atomic physics, enabling highly accurate calculations that were previously infeasible.
Source: https://www.nist.gov/itl/math/computation-atomic-properties-hy-ci-method
Keywords: Hylleraas, Energies, Inter-electronic, Atomic, Properties
