Accurate ab initio spin densities

Details Accurate ab initio spin densities Accurate ab initio spin densities

2012-03-17

arxiv.org/abs/1203.3888v1

Physics

Chemical Physics

37 pages, 13 figures

Scientific paper

We present an approach for the calculation of spin density distributions for molecules that require very large active spaces for a qualitatively correct description of their electronic structure. Our approach is based on the density-matrix renormalization group (DMRG) algorithm to calculate the spin density matrix elements as basic quantity for the spatially resolved spin density distribution. The spin density matrix elements are directly determined from the second-quantized elementary operators optimized by the DMRG algorithm. As an analytic convergence criterion for the spin density distribution, we employ our recently developed sampling-reconstruction scheme [J. Chem. Phys. 2011, 134, 224101] to build an accurate complete-active-space configuration-interaction (CASCI) wave function from the optimized matrix product states. The spin density matrix elements can then also be determined as an expectation value employing the reconstructed wave function expansion. Furthermore, the explicit reconstruction of a CASCI-type wave function provides insights into chemically interesting features of the molecule under study such as the distribution of $\alpha$- and $\beta$-electrons in terms of Slater determinants, CI coefficients, and natural orbitals. The methodology is applied to an iron nitrosyl complex which we have identified as a challenging system for standard approaches [J. Chem. Theory Comput. 2011, 7, 2740].

Affiliated with

Also associated with

No associations

Rating

Accurate ab initio spin densities does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Accurate ab initio spin densities, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Accurate ab initio spin densities will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-313236