Ground state of the Fe(<scp>ii</scp>)-porphyrin model system corresponds to quintet: a DFT and DMRG-based tailored CC study

Antalík, Andrej; Nachtigallová, Dana; Lo, Rabindranath; Matoušek, Mikuláš; Lang, Jakub; Legeza, Örs; Pittner, Jiřı́; Hobza, Pavel; Veis, Libor

doi:10.1039/d0cp03086d

Cited by 18 publications

(32 citation statements)

References 53 publications

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“…In the present study, we were interested solely in the scaling characteristics of our parallel scheme, we therefore do not present any energies (they would be out of context anyway). Nevertheless, the detailed study of the Fe(II)‐porphyrin model was already published elsewhere 62 and chemistry‐oriented articles about the remaining two systems should also appear soon.…”

Section: Resultsmentioning

confidence: 99%

“…In fact, the MPS matrices are nothing, but reshaped renormalization matrices ), and they are easily obtainable from the DMRG sweep algorithm 43 . They can be used for example, for efficient calculations of correlation functions or a subset of the FCI expansion coefficients, which may be employed for the purposes of the tailored coupled cluster methods 39,58–62 . If we reshape

O_{l_{p - 1} s, l_{p}}^{L}

) to

L_{l_{p - 1}, l_{p}}^{s}

(i.e., 4 M × M matrix into M × M × 4 tensor) and similarly for the right block matrix, then starting with the wave function expansion in the renormalized basis ) and recursive application of ) would lead to

(|, (Ψ_{MPS}〉) = \sum_{\{s\}} L^{s_{1}} L^{s_{2}} \dots ψ^{s_{i} s_{i + 1}} \dots R^{s_{n}} . (|, (s_{1} s_{2} \dots s_{n}〉)

which is the two‐site MPS form of the DMRG wave function.…”

Section: Theorymentioning

confidence: 99%

“…Fe(II)‐porphyrin model was selected, because it was demonstrated by Li Manni et al 64,65 that apart from 3 d , 4 d , and 4 s orbitals of the Fe center and σ (Fe‐N) orbital, inclusion of all π orbitals from the porphyrin ring into the active space is necessary for a quantitative determination of its ground state, leading to CAS(32,34). In our recent DMRG‐DLPNO‐TCCSD(T) study, 62 we have optimized this CAS orbitals for the lowest triplet and quintet states and different geometries by means of the state specific DMRG‐CASSCF method in TZVP basis. In the present study, we have tested the parallel QC‐DMRG scaling on the above mentioned triplet state DMRG‐CASSCF(32,34)/TZVP orbitals optimized at the geometry used in Li Manni et al works 64,65 .…”

Section: Computational Detailsmentioning

confidence: 99%

“…In the present study, we have tested the parallel QC‐DMRG scaling on the above mentioned triplet state DMRG‐CASSCF(32,34)/TZVP orbitals optimized at the geometry used in Li Manni et al works 64,65 . The triplet state was chosen as it is more correlated than quintet 62,64 and the active space orbitals were split‐localized 23 …”

Section: Computational Detailsmentioning

confidence: 99%

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Massively parallel quantum chemical density matrix renormalization group method

et al. 2020

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We present, to the best of our knowledge, the first attempt to exploit the super‐computer platform for quantum chemical density matrix renormalization group (QC‐DMRG) calculations. We have developed the parallel scheme based on the in‐house MPI global memory library, which combines operator and symmetry sector parallelisms, and tested its performance on three different molecules, all typical candidates for QC‐DMRG calculations. In case of the largest calculation, which is the nitrogenase FeMo cofactor cluster with the active space comprising 113 electrons in 76 orbitals and bond dimension equal to 6000, our parallel approach scales up to approximately 2000 CPU cores.

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Section: Resultsmentioning

confidence: 99%

O_{l_{p - 1} s, l_{p}}^{L}

) to

L_{l_{p - 1}, l_{p}}^{s}

(|, (Ψ_{MPS}〉) = \sum_{\{s\}} L^{s_{1}} L^{s_{2}} \dots ψ^{s_{i} s_{i + 1}} \dots R^{s_{n}} . (|, (s_{1} s_{2} \dots s_{n}〉)

which is the two‐site MPS form of the DMRG wave function.…”

Section: Theorymentioning

confidence: 99%

Section: Computational Detailsmentioning

confidence: 99%

Section: Computational Detailsmentioning

confidence: 99%

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Massively parallel quantum chemical density matrix renormalization group method

et al. 2020

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“…38 For comparison with the SC-NEVPT2 results, we employed the small complete active space (CAS) comprising 8 electrons in 11 orbitals (3d and 4d orbitals of Fe together with one σ Fe-N orbital). 38 The large (production) active space, CAS (40,42), is equivalent to the active space used in our previous Fe(II)-porphyrin model study, 55 where we have shown that such a large CAS is necessary for quantitatively correct results. This active space contains the 3d, 4s, 4p, and 4d orbitals of Fe, the four σ Fe-N orbitals, and the complete π space of the conjugated porphyrin ring.…”

Section: Computational Detailsmentioning

confidence: 91%

Density matrix renormalization group with dynamical correlation via adiabatic connection

Beran¹,

Matoušek²,

Hapka³

et al. 2021

Preprint

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The quantum chemical version of the density matrix renormalization group (DMRG) method has established itself as one of the methods of choice for calculations of strongly correlated molecular systems. Despite its great ability to capture strong electronic correlation in large active spaces, it is not suitable for computations of dynamical electron correlation. In this work, we present a new approach to the electronic structure problem of strongly correlated molecules, in which DMRG is responsible for a proper description of the strong correlation, whereas dynamical correlation is computed via the recently developed adiabatic connection (AC) technique, which requires only up to two-body active space reduced density matrices. We report encouraging results of this approach on typical candidates for DMRG computations, namely the n-acenes (n = 2 → 7), Fe(II)-porphyrin, and Fe 3 S 4 cluster.

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Ab Initio Methods in First‐Row Transition Metal Chemistry

Feldt

Phung

2022

Eur J Inorg Chem

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Molecules containing 3d transition metals (TMs) are usually associated with versatile reactivity, partly due to their complicated electronic structures involving multiple close‐lying spin states. An accurate description of different electronic states is notoriously difficult and still a challenge for computational methodologies. Density functional theory, although repeatedly shown to give less reliable results for near‐degeneracy problems, remains the workhorse to explore the reactivity of TM complexes. Ab initio wavefunction theory has been lagging behind due to its high computational cost. However, tremendous efforts have been put to improve their applicability over the past few years, particularly local coupled cluster and low‐scaling multireference methods. In this mini‐review, we highlight major advancements of these ab initio techniques and discuss their recent applications in the calculations of spin state energetics of first‐row TM complexes, ranging from spin crossover compounds and metalloproteins to biomimetic complexes capable of activating C−H bonds.

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Ground state of the Fe(ii)-porphyrin model system corresponds to quintet: a DFT and DMRG-based tailored CC study

Abstract: Fe(II)-porphyrins play an important role in many reactions relevant to material science and biological processes, due to their closely lying spin states. Although the prevalent opinion is that these systems...

Cited by 18 publications

References 53 publications

Massively parallel quantum chemical density matrix renormalization group method

Massively parallel quantum chemical density matrix renormalization group method

Density matrix renormalization group with dynamical correlation via adiabatic connection

Ab Initio Methods in First‐Row Transition Metal Chemistry

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