Communication: DMRG-SCF study of the singlet, triplet, and quintet states of oxo-Mn(Salen)

Wouters, Sebastian; Bogaerts, Thomas; Voort, Pascal Van Der; Speybroeck, Véronique Van; Neck, Dimitri Van

doi:10.1063/1.4885815

Cited by 91 publications

(132 citation statements)

References 64 publications

Supporting

Mentioning

123

Contrasting

Unclassified

Order By: Relevance

“…The mechanism of the epoxidation is not clear, with various experiments providing evidence supporting at least three different possibilities 84,85 . To provide further clarification, several theoretical studies [86][87][88][89][90][91][92][93][94][95][96] have tried to understand the electronic structure of these clusters. The chlorine containing neutral oxo-Mn(salen) model cluster studied in this work is shown in Figure 3.…”

Section: Oxo-mn(salen)mentioning

confidence: 99%

“…Here we perform MRLCC and NEVPT2 calculations on the singlet and triplet ground states of the oxoMn(salen) using the optimized geometry obtained by Ivanic et al 91 Based on recommendation by Wouters et al 92 a (28e,22o) active space was used to perform the DMRG-SCF calculations 97,98 where the DMRG calculation during each iteration was performed with an M of 2000. HOMO-13 to LUMO+7 canonical Hartree Fock orbitals were included in the active space in the first iteration.…”

Section: Oxo-mn(salen)mentioning

confidence: 99%

See 1 more Smart Citation

Combining Internally Contracted States and Matrix Product States To Perform Multireference Perturbation Theory

Sharma

Knizia

Guo

et al. 2017

J. Chem. Theory Comput.

View full text Add to dashboard Cite

We present two efficient and intruder-free methods for treating dynamic correlation on top of general multi-configuration reference wave functions-including such as obtained by the density matrix renormalization group (DMRG) with large active spaces. The new methods are the second order variant of the recently proposed multi-reference linearized coupled cluster method (MRLCC) [S. Sharma, A. Alavi, J. Chem. Phys. 143, 102815 (2015)], and of N-electron valence perturbation theory (NEVPT2), with expected accuracies similar to MRCI+Q and (at least) CASPT2, respectively. Great efficiency gains are realized by representing the first-order wave function with a combination of internal contraction (IC) and matrix product state perturbation theory (MPSPT). With this combination, only third order reduced density matrices (RDMs) are required. Thus, we obviate the need for calculating (or estimating) RDMs of fourth or higher order; these had so far posed a severe bottleneck for dynamic correlation treatments involving the large active spaces accessible to DMRG. Using several benchmark systems, including first and second row containing small molecules, Cr2, pentacene and oxo-Mn(Salen), we shown that active spaces containing at least 30 orbitals can be treated using this method. On a single node, MRLCC2 and NEVPT2 calculations can be performed with over 550 and 1100 virtual orbitals, respectively. We also critically examine the errors incurred due to the three sources of errors introduced in the present implementation -calculating second order instead of third order energy corrections, use of internal contraction and approximations made in the reference wavefunction due to DMRG.

show abstract

Section: Oxo-mn(salen)mentioning

confidence: 99%

Section: Oxo-mn(salen)mentioning

confidence: 99%

Combining Internally Contracted States and Matrix Product States To Perform Multireference Perturbation Theory

Sharma

Knizia

Guo

et al. 2017

J. Chem. Theory Comput.

View full text Add to dashboard Cite

show abstract

“…excitation expansion around a single-reference, and is thus well suited to non-mean-field, or strongly correlated, electronic structure, such as arising in transition-metal chemistry. Here, the DMRG has so far been applied in a complete active space setting, 8,38,[47][48][49][50][51] starting with the early work of Reiher and coworkers, 47 to the latest calculations on systems as large as the bioinorganic Mn 4 Ca core of photosystem II by Kurashige et al, 52 and the ubiquitous [4Fe-4S] biological iron-sulfur complexes by Sharma et al; 53 these have active spaces in excess of 50 orbitals. Finally, the internal structure of the MPS means that it is uniquely suited to pseudo-onedimensional correlation, and in the ab-initio chemical context, the DMRG has been used since its inception to study groundand excited-states of π-conjugated molecules, 27,54,55 such as the polyacenes 55 and graphene nanoribbons, 49 as well as other one-dimensional systems, such as atomic chains and rings.…”

Section: Introductionmentioning

confidence: 99%

The ab-initio density matrix renormalization group in practice

Olivares‐Amaya

Nakatani

et al. 2015

The Journal of Chemical Physics

355

552

View full text Add to dashboard Cite

The ab-initio density matrix renormalization group (DMRG) is a tool that can be applied to a wide variety of interesting problems in quantum chemistry. Here, we examine the density matrix renormalization group from the vantage point of the quantum chemistry user. What kinds of problems is the DMRG well-suited to? What are the largest systems that can be treated at practical cost? What sort of accuracies can be obtained, and how do we reason about the computational difficulty in different molecules? By examining a diverse benchmark set of molecules: π-electron systems, benchmark main-group and transition metal dimers, and the Mn-oxo-salen and Fe-porphine organometallic compounds, we provide some answers to these questions, and show how the density matrix renormalization group is used in practice. C 2015 AIP Publishing LLC. [http://dx

show abstract

“…This ansatz was first exploited for DMRG-SCF in the [augmented Hessian (AH)] Newton-Raphson-like (NR) implementation by Ghosh and co-workers 26 and Wouters et al 36,37 . Its implementation was also described by Ma and Ma 38 who, in addition, presented a pilot DMRG-SCF implementation of the Werner-Meyer (WM) MCSCF algorithm 39 .…”

Section: Introductionmentioning

confidence: 99%

Second-Order Self-Consistent-Field Density-Matrix Renormalization Group

Knecht

Keller

et al. 2017

J. Chem. Theory Comput.

View full text Add to dashboard Cite

We present a matrix-product state (MPS)-based quadratically convergent densitymatrix renormalization group self-consistent-field (DMRG-SCF) approach. Following a proposal by Werner and Knowles (J. Chem. Phys. 82, 5053, (1985)), our DMRG-SCF algorithm is based on a direct minimization of an energy expression which is correct to second-order with respect to changes in the molecular orbital basis. We exploit a simultaneous optimization of the MPS wave function and molecular orbitals in order to achieve quadratic convergence. In contrast to previously reported (augmented Hessian) Newton-Raphson and super-configuration-interaction algorithms for DMRG-SCF, energy convergence beyond a quadratic scaling is possible in our ansatz.Discarding the set of redundant active-active orbital rotations, the DMRG-SCF energy converges typically within two to four cycles of the self-consistent procedure.

show abstract

Communication: DMRG-SCF study of the singlet, triplet, and quintet states of oxo-Mn(Salen)

Cited by 91 publications

References 64 publications

Combining Internally Contracted States and Matrix Product States To Perform Multireference Perturbation Theory

Combining Internally Contracted States and Matrix Product States To Perform Multireference Perturbation Theory

The ab-initio density matrix renormalization group in practice

Second-Order Self-Consistent-Field Density-Matrix Renormalization Group

Contact Info

Product

Resources

About