The OpenMolcas <i>Web</i>: A Community-Driven Approach to Advancing Computational Chemistry

Manni, Giovanni Li; Galván, Ignacio Fernández; Alavi, Ali; Aleotti, Flavia; Aquilante, Francesco; Autschbach, Jochen; Avagliano, Davide; Baiardi, Alberto; Bao, Jie J.; Battaglia, Stefano; Birnoschi, Letitia; Blanco-González, Alejandro; Bokarev, Sergey I.; Broer, Ria; Cacciari, Roberto; Calio, Paul B.; Carlson, Rebecca K.; Couto, Rafael C.; Cerdán, Luis; Chibotaru, Liviu F.; Chilton, Nicholas F.; Church, Jonathan R.; Conti, Irene; Coriani, Sonia; Cuéllar-Zuquin, Juliana; Daoud, Razan E.; Dattani, Nike; Decleva, Piero; Graaf, Coen de; Delcey, Mickaël G.; Vico, Luca De; Dobrautz, Werner; Dong, Sijia S.; Feng, Rulin; Ferré, Nicolas; Filatov, Michael; Gagliardi, Laura; Garavelli, Marco; González, Leticia; Guan, Yafu; Guo, Meiyuan; Hennefarth, Matthew R.; Hermes, Matthew R.; Hoyer, Chad E.; Huix‐Rotllant, Miquel; Jaiswal, Vishal K.; Kaiser, Andy; Kaliakin, Danil S.; Khamesian, Marjan; King, Daniel S.; Kochetov, Vladislav; Krośnicki, M.; Kumaar, Arpit Arun; Larsson, Ernst D.; Lehtola, Susi; Lepetit, Marie-Bernadette; Lischka, Hans; Ríos, Pablo López; Lundberg, Marcus; Ma, Dongxia; Mai, Sebastian; Marquetand, Philipp; Merritt, Isabella C. D.; Montorsi, Francesco; Mörchen, Maximilian; Nenov, Artur; Nguyen, Vu Ha Anh; Nishimoto, Yoshio; Oakley, Meagan S.; Olivucci, Massimo; Oppel, Markus; Padula, Daniele; Pandharkar, Riddhish; Phung, Quan Manh; Plasser, Felix; Raggi, Gerardo; Rebolini, Elisa; Reiher, Markus; Rivalta, Ivan; Roca‐Sanjuán, Daniel; Romig, Thies; Safari, Arta Anushirwan; Sánchez-Mansilla, Aitor; Sand, Andrew M.; Schapiro, Igor; Scott, Thais R.; Segarra‐Martí, Javier; Segatta, Francesco; Sergentu, Dumitru‐Claudiu; Sharma, Prachi; Shepard, Ron; Shu, Yinan; Staab, Jakob K.; Straatsma, Tjerk P.; Sørensen, Lasse Kragh; Tenório, Bruno Nunes Cabral; Truhlar, Donald G.; Ungur, Liviu; Vacher, Morgane; Veryazov, Valera; Voß, Torben Arne; Weser, Oskar; Wu, Dihua; Yang, Xuchun; Yarkony, David R.; Zhou, Chen; Zobel, J. Patrick; Lindh, Roland

doi:10.1021/acs.jctc.3c00182

Cited by 106 publications

(77 citation statements)

References 555 publications

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“…Similarly, we evaluated oscillator strengths at S 1 equilibrium geometries, since that is the relevant point for the emission process. State-average-CASSCF (SA-CASSCF) and multi-state-CASPT2 (MS-CASPT2) calculations were carried out with the (Open)Molcas software, − including 5 singlet or triplet states and adopting the ANO-L-VDZP basis set. SA-CASSCF is a flavor of CASSCF aimed at obtaining compromise wavefunctions for all states included, avoiding root-flipping problems, while MS-CASPT2 is a multireference perturbative correction to energy also able to take into account the fact that the wavefunction is not dominated by a single Slater determinant, in analogy to the previously used NEVPT2, and to introduce the effect of dynamic correlation on top of multiple SA-CASSCF wavefunctions, especially well suited for regions of the potential energy surfaces or electronic states where CASPT2 might fail .…”

Section: Resultsmentioning

confidence: 99%

Identification of Unknown Inverted Singlet–Triplet Cores by High-Throughput Virtual Screening

Omar,

Xie,

Troisi

et al. 2023

J. Am. Chem. Soc.

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Molecules where the energy of the lowest excited singlet state is found below the energy of the lowest triplet state (inverted singlet–triplet molecules) are extremely rare. It is particularly challenging to discover new ones through virtual screening because the required wavefunction-based methods are expensive and unsuitable for high-throughput calculations. Here, we devised a virtual screening approach where the molecules to be considered with advanced methods are pre-selected with increasingly more sophisticated filters that include the evaluation of the HOMO-LUMO exchange integral and approximate CASSCF calculations. A final set of 7 candidates (0.05% of the initial 15 000) were verified to possess inversion between singlet and triplet states with state-of-the-art multireference methods (MS-CASPT2). One of them is deemed of particular interest because it is unrelated to other proposals made in the literature.

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Section: Resultsmentioning

confidence: 99%

Identification of Unknown Inverted Singlet–Triplet Cores by High-Throughput Virtual Screening

Omar,

Xie,

Troisi

et al. 2023

J. Am. Chem. Soc.

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“…Coupled-cluster calculations were performed using the Molpro package . CASPT2 and MC-PDFT calculations were conducted with OpenMolcas. ,, NEVPT, CB-MRPT, SDS-, and MRCISD calculations were performed using the Beijing Density Functional (BDF) program package. − The Forte plugin to Psi4 was used to perform DSRG-based calculations. The CEPT2 calculations were done with an in-house quantum chemistry program package (ORZ) …”

Section: Computational Detailsmentioning

confidence: 99%

Unraveling the Spin-State Energetics of FeN₄ Complexes with Ab Initio Methods

Phung,

Nam,

Saitow

2023

J. Phys. Chem. A

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A systematic analysis was conducted to explore the spin-state energetics of a series of 19 FeN4 complexes. The performance of a large number of multireference methods was assessed, highlighting the significant challenges associated with accurately describing the spin-state energetics of FeN4 complexes. Most multireference methods were found to be susceptible to errors originating from the reference CASSCF wavefunction, leading to an overstabilization of high-spin states. Nonetheless, a few multireference methods, namely, CASPT2/CC, DSRG-MRPT3, and LDSRG(2), demonstrated promising performance compared to the benchmark CCSD(T) method. Furthermore, our study revealed that FeN4 complexes having a quintet ground state are exceedingly rare. Accordingly, only one specific model (Fe(L2)) and one synthesized complex (Fe(OTBP)) have the quintet ground state among the studied complexes. This scarcity of quintet FeN4 complexes highlights the unique nature of these systems and raises intriguing questions regarding the factors influencing spin states, such as the size of the macrocycle cavity, the introduction of substituents, or the induction of out-of-plane deformation.

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“…We note that we checked larger slabs up to a 9 × 9 × 9 expansion and still did not observe convergence (Figure S8). The electrostatic potential can be converged very quickly in reciprocal space using Ewald summation, but this method is not available in OpenMolcas . Luckily, there are two methods that can be employed to address this issue: the first uses an extra set of charges external to the crystalline slab as fitting parameters to replicate the exact infinite crystalline potential , and the second places an approximately spherical array of unit cells in a perfect conductor to screen the charges directly, thus approximating the infinite crystalline potential very closely.…”

Section: Resultsmentioning

confidence: 99%

Accurate and Efficient Spin–Phonon Coupling and Spin Dynamics Calculations for Molecular Solids

Nabi,

Staab,

Mattioni

et al. 2023

J. Am. Chem. Soc.

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Molecular materials are poised to play a significant role in the development of future optoelectronic and quantum technologies. A crucial aspect of these areas is the role of spin− phonon coupling and how it facilitates energy transfer processes such as intersystem crossing, quantum decoherence, and magnetic relaxation. Thus, it is of significant interest to be able to accurately calculate the molecular spin−phonon coupling and spin dynamics in the condensed phase. Here, we demonstrate the maturity of ab initio methods for calculating spin−phonon coupling by performing a case study on a single-molecule magnet and showing quantitative agreement with the experiment, allowing us to explore the underlying origins of its spin dynamics. This feat is achieved by leveraging our recent developments in analytic spin−phonon coupling calculations in conjunction with a new method for including the infinite electrostatic potential in the calculations. Furthermore, we make the first ab initio determination of phonon lifetimes and line widths for a molecular magnet to prove that the commonplace Born−Markov assumption for the spin dynamics is valid, but such "exact" phonon line widths are not essential to obtain accurate magnetic relaxation rates. Calculations using this approach are facilitated by the open-source packages we have developed, enabling cost-effective and accurate spin−phonon coupling calculations on molecular solids.

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The OpenMolcas Web: A Community-Driven Approach to Advancing Computational Chemistry

Cited by 106 publications

References 555 publications

Identification of Unknown Inverted Singlet–Triplet Cores by High-Throughput Virtual Screening

Identification of Unknown Inverted Singlet–Triplet Cores by High-Throughput Virtual Screening

Unraveling the Spin-State Energetics of FeN₄ Complexes with Ab Initio Methods

Accurate and Efficient Spin–Phonon Coupling and Spin Dynamics Calculations for Molecular Solids

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The OpenMolcas Web: A Community-Driven Approach to Advancing Computational Chemistry

Cited by 106 publications

References 555 publications

Identification of Unknown Inverted Singlet–Triplet Cores by High-Throughput Virtual Screening

Identification of Unknown Inverted Singlet–Triplet Cores by High-Throughput Virtual Screening

Unraveling the Spin-State Energetics of FeN4 Complexes with Ab Initio Methods

Accurate and Efficient Spin–Phonon Coupling and Spin Dynamics Calculations for Molecular Solids

Contact Info

Product

Resources

About

Unraveling the Spin-State Energetics of FeN₄ Complexes with Ab Initio Methods