Asymptotic Correction Scheme to Semilocal Exchange-Correlation Functionals

• Main Authors: Chi-Ruei Pan, 潘祈叡
• Other Authors: Jeng-Da Chai
• Format: Others
• Language: en_US
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/j8k59b

碩士 === 國立臺灣大學 === 物理研究所 === 100 === Aiming to correct the asymptotic behavior of semilocal exchange-correlation (XC) functionals for finite system, we proposed a correction scheme, wherein an exchange energy density functional whose functional derivative has the exact −1/r asymptote can be added to any semilocal XC functional, as the double-counting energy can be easily discounted. Applying this asymptotic correction scheme to the Perdew-Burke-Ernzerhof functional, the predicted highest-occupied-molecular-orbital (HOMO) energies and Rydberg excitation energies of molecules are shown to be significantly improved. A computationally efficient method which is called the Resolution of the identity (RI) that has been implemented. This method can converge to the exact LFA faster than the numerical LFA method which evaluates LFA functional by performing numerical quadrature. With the great advancement in the efficiency, LFA is made practical for large system.