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A configuration‐interaction‐oriented implementation of the complex coordinate method
Author(s) -
Saenz Alejandro,
Weyrich Wolf,
Froelich Piotr
Publication year - 1993
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560460304
Subject(s) - hamiltonian (control theory) , representation (politics) , ab initio , configuration interaction , matrix (chemical analysis) , context (archaeology) , atom (system on chip) , matrix representation , helium , computer science , kinetic energy , atomic physics , physics , molecule , computational science , computational physics , chemistry , quantum mechanics , mathematics , mathematical optimization , paleontology , chromatography , politics , political science , law , group (periodic table) , biology , embedded system
An implementation of the complex coordinate method is demonstrated that exploits a new technique for obtaining the matrix representation of the complex dilated Hamiltonian. The purpose is to make the complex coordinate method applicable together with standard numerical ab initio codes designed for large‐scale calculations on many‐electron atoms and/or molecules. No complex intergrals have to be calculated, and no changes of the standard codes are required even in the common case where the kinetic and potential energy components are not stored separately. Instead, two standard (real) CI calculations are used to generate the dilated (complex) CI matrix representation. The performance of the procedure is demonstrated in the context of the GAMESS program and applied to obtain the resonant structure of the Bethe surface pertinent to the absorption spectrum of the helium atom. © 1993 John Wiley & Sons, Inc.