Spinor optimization for a relativistic spin-dependent CASSCF program

详细信息    查看全文

• 作者：Timo Fleig ; Christel M. Marian and Jeppe Olsen
• 关键词：Key words ; Relativistic two ; component quantum chemical methods ; Complete ; active ; space ; SCF theory ; Spin ; orbit coupling ; Spin ; dependent one ; particle bases
• 刊名：Theoretical Chemistry Accounts: Theory, Computation, and Modeling (Theoretica Chimica Acta)
• 出版年：1997
• 出版时间：October 1997
• 年：1997
• 卷：97
• 期：1-4
• 页码：125-135
• 全文大小：476 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Theoretical and Computational Chemistry
  Inorganic Chemistry
  Organic Chemistry
  Physical Chemistry
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1432-2234

文摘

Detailed formulae for the implementation of the multi-configuration SCF spinor optimization in a basis of Kramers pair 2-spinors – i.e. exploiting time-reversal symmetry – are presented. Full expressions for the spinor gradient and spinor Hessian elements are given in abstract form as well as within the usual CASSCF subspace division. As far as possible, the resulting terms are grouped to relativistic inactive and active Fock matrices, which have been introduced previously. Approximations for the Hessian are introduced so as to initialize it in an inverse Hessian update algorithm for a diagonal first approximation within the standard quasi-Newton-Raphson procedure. The effects of double group symmetry arising from spin dependence on Fock matrices and therefore gradient and Hessian are discussed and a group scheme for the implementation is proposed.