TY - GEN

T1 - Breaking the curse of the non-dynamical correlation problem

T2 - The spin - Flip method

AU - Krylov, Anna I.

AU - Slipchenko, Lyudmila V.

AU - Levchenko, Sergey V.

PY - 2007

Y1 - 2007

N2 - The spin-flip approach to multi-reference situations (e.g., bond-breaking and diradicals) is described. Both closed and open shell singlet states are described within a single reference formalism as spin-flipping, e.g., a → β, excitations from a triplet (M5=1) reference state for which both dynamical and non-dynamical correlation effects are much smaller than for the corresponding singlet state. Formally, the new theory can be viewed as an Equation-of-Motion model where excited states are sought in the basis of determinants conserving the total number of electrons but changing the number of α and β electrons.

AB - The spin-flip approach to multi-reference situations (e.g., bond-breaking and diradicals) is described. Both closed and open shell singlet states are described within a single reference formalism as spin-flipping, e.g., a → β, excitations from a triplet (M5=1) reference state for which both dynamical and non-dynamical correlation effects are much smaller than for the corresponding singlet state. Formally, the new theory can be viewed as an Equation-of-Motion model where excited states are sought in the basis of determinants conserving the total number of electrons but changing the number of α and β electrons.

UR - http://www.scopus.com/inward/record.url?scp=36849014250&partnerID=8YFLogxK

U2 - 10.1021/bk-2007-0958.ch006

DO - 10.1021/bk-2007-0958.ch006

M3 - Conference contribution

AN - SCOPUS:36849014250

SN - 084123843X

SN - 9780841238435

T3 - ACS Symposium Series

SP - 89

EP - 102

BT - Electron Correlation Methodology

PB - American Chemical Society

ER -