AB INITIO R-MATRIX/MULTI-CHANNEL QUANTUM DEFECT THEORY APPROACH TO STUDY MOLECULAR CORE EXCITATION AND IONIZATION: GSCF4R

Abstract

The ab initio program package named GSCF4R, which is based on the polyatomic R-matrix/MQDT (multi-channel quantum defect theory), has been developed using Gaussian type basis functions for the bound and continuum states to analyze the near edge feature of molecular inner shell excitations. The GSCF4R code is constructed by improvement and extension of the ordinal static exchange (STEX) approach. The R-matrix approach used in GSCF4R is beyond multi-channel multi-reference extensions of STEX, since it is based on the close coupling method augmented with the correlation term solved in the inner part of the R-matrix sphere. Simplification of the input data in GSCF4R has demonstrated that the R-matrix/MQDT method could be widely used in analysis of the molecular inner shell excitation and ionization. The quantum defects of the Rydberg states converging to the lowest valence ionized state NO +(1∑+) and the lowest N1 s ionized state N ⋆ O +(3Π) have been calculated.